Can Wafer style butterfly valves be used for dead-end service?

No. Wafer valves rely on the compression from both the upstream and downstream flanges to remain in the line. If the downstream flange is removed, the valve falls out. Lug style valves are required for dead-end service as they are independently bolted to the upstream flange.

How many bolts does a Lug valve require compared to a Wafer valve?

A Lug valve typically requires twice as many bolts (cap screws) as a Wafer valve. For example, on a 6-inch Class 150 flange with 8 holes, a Wafer valve uses 8 long through-bolts, while a Lug valve uses 16 shorter cap screws (8 for the upstream side and 8 for the downstream side).

How do you calculate the stud length for a Wafer valve?

To calculate the required stud length (L) for a Wafer valve: Add the Valve Body Width + 2x Flange Thickness + 2x Gasket Thickness + 2x Nut Height + enough length for approximately 3 exposed threads.

Why are bolt lengths estimated for Lug valves?

Lug bolt (cap screw) lengths must be calculated precisely because the bolt cannot bottom out in the lug, nor can it be too short to engage the threads fully. The formula is typically: Flange Thickness + Gasket + Washer + (1.0x to 1.5x Bolt Diameter for engagement) . Always verify thread depth with the valve manufacturer.

What standards apply to butterfly valve bolting?

Bolting must match the flange standard used in the piping system. Common standards include ASME B16.5/B16.47 (Class 150-900), EN 1092-1 (PN 6-100), JIS (5K-20K), and AS 2129 (Table D/E). It is critical to verify the bolt circle diameter and thread pitch before installation.

The Ultimate Butterfly Valve Bolt Size & Length Chart

Q: What is the difference between Lug and Wafer butterfly valve bolting?

The fundamental difference lies in the mechanism. Wafer valves are clamped between two pipe flanges using long through-bolts (studs) that pass through the entire assembly. Lug valves feature threaded inserts and are bolted to each flange independently using shorter cap screws.

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WAFER STYLE

ASME

ASME Class 150 ASME Class 300 ASME Class 600 ASME Class 900

EN 1092-1 PN 6 EN 1092-1 PN 10 EN 1092-1 PN 16 EN 1092-1 PN 25 EN 1092-1 PN 40 EN 1092-1 PN 63 EN 1092-1 PN 100

DIN

DIN PN6 DIN PN10 DIN PN16 DIN PN25 DIN PN40 DIN PN64 DIN PN100

BS PN6 BS PN10 BS PN16 BS PN40 BS PN64

JIS

JIS 5K JIS 10K JIS 16K JIS 20K

AS Table D AS Table E AS Table F AS Table H

GOST

GOST PN6 GOST PN10 GOST PN16 GOST PN25 GOST PN40 GOST PN63 GOST PN100

LUG STYLE

ASME

ASME Class 150 & 125 ASME Class 300 ASME Class 600 ASME Class 900

EN 1092-1 PN 6 EN 1092-1 PN 10 EN 1092-1 PN 16 EN 1092-1 PN 25 EN 1092-1 PN 40 EN 1092-1 PN 63 EN 1092-1 PN 100

JIS

JIS 5K JIS 10K JIS 16K JIS 20K

AS Table D AS Table E AS Table F

GOST

GOST PN6 GOST PN10 GOST PN16 GOST PN25 GOST PN40 GOST PN63 GOST PN100

GUIDES

Lug vs. Wafer Other Standards Golden Rules Contact

Lug vs. Wafer: Understanding the Bolting Difference

The fundamental difference between Lug and Wafer butterfly valves dictates their bolting method and application range, especially in critical dead-end service.

Wafer Style (Through-Bolts)

Wafer valves are "sandwiched" between two pipe flanges. They rely on long through-bolts (or studs with nuts on each end) that pass through both flanges and the valve body's unthreaded guide holes. The tension from these bolts clamps the entire assembly together.

Mechanism: Clamped by tension from long bolts passing through the entire assembly.
Key Feature: Valve cannot remain in the line if the downstream flange is removed (no dead-end service).
Advantage: Typically more cost-effective and lighter.

Lug Style (Cap Screws)

Lug valves feature threaded inserts ("lugs") in the valve body that align with the bolt holes of the flanges. Each flange is bolted to the valve body independently using shorter cap screws (bolts).

Mechanism: Each flange is independently bolted to the valve's threaded lugs.
Key Feature: Allows for dead-end service, where the downstream piping can be removed while the valve maintains a seal against upstream pressure.
Advantage: Essential for maintenance-heavy applications and end-of-line service.

LUG VS. WAFER BOLT COUNT

For a given flange standard, a Lug-style valve will use twice as many bolts as a Wafer-style valve. For example, a 6" Class 150 flange has 8 bolt holes. A wafer valve will use 8 long through-bolts, while a lug valve will use 16 shorter cap screws (8 for the upstream flange, 8 for the downstream flange).

ASME Class 150 Wafer Valve Bolt Chart

Through-Bolt requirements for installation between ASME B16.5 & B16.47 Flanges

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (in)	DN (mm)	Qty	Diameter (in)	Thread Standard	Wrench Size (Heavy Hex)	Rec. Length (L)* (in)
Standard: ASME B16.5 (Up to 24")
2	50	4	5/8	UNC	1-1/16	4.50
2.5	65	4	5/8	UNC	1-1/16	4.75
3	80	4	5/8	UNC	1-1/16	5.00
4	100	8	5/8	UNC	1-1/16	5.00
5	125	8	3/4	UNC	1-1/4	5.50
6	150	8	3/4	UNC	1-1/4	5.50
8	200	8	3/4	UNC	1-1/4	6.00
10	250	12	7/8	UNC	1-7/16	6.50
12	300	12	7/8	UNC	1-7/16	7.00
14	350	12	1	8UN	1-5/8	7.50
16	400	16	1	8UN	1-5/8	8.00
18	450	16	1-1/8	8UN	1-13/16	8.75
20	500	20	1-1/8	8UN	1-13/16	9.50
24	600	20	1-1/4	8UN	2	10.50
Standard: ASME B16.47 Series A (MSS SP-44) - Large Diameter
26	650	24	1-1/4	8UN	2	11.50
30	750	28	1-1/4	8UN	2	12.50
36	900	32	1-1/2	8UN	2-3/8	14.00
Standard: ASME B16.47 Series B (API 605) - Note: Smaller Bolts
26	650	36	3/4	UNC	1-1/4	Check Factory
30	750	44	3/4	UNC	1-1/4	Check Factory
36	900	44	1	8UN	1-5/8	Check Factory

* Important Notes on Bolt Length:

Calculation Basis: Lengths are estimated based on API 609 Category A Body Width + 2x Standard Flange Thickness + Gaskets + Nuts + 3 threads exposed.
Thread Standard: Bolts > 1" diameter are listed as 8UN (8 Threads Per Inch) per ASTM A193 B7 standard, unless UNC is specifically requested.
Verification: Always verify the exact face-to-face dimension of the supplied valve before ordering bulk hardware.

ASME Class 300 Wafer Valve Bolt Chart

Through-Bolt requirements for installation between ASME B16.5 & B16.47 Flanges

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (in)	DN (mm)	Qty	Diameter (in)	Thread Standard	Wrench Size (Heavy Hex)	Rec. Length (L) (in)
Standard: ASME B16.5 (Up to 24")
2	50	8	5/8	UNC	1-1/16	5.00
2.5	65	8	3/4	UNC	1-1/4	5.50
3	80	8	3/4	UNC	1-1/4	5.75
4	100	8	3/4	UNC	1-1/4	6.00
5	125	8	3/4	UNC	1-1/4	6.50
6	150	12	3/4	UNC	1-1/4	6.75
8	200	12	7/8	UNC	1-7/16	7.50
10	250	16	1	8UN	1-5/8	8.50
12	300	16	1-1/8	8UN	1-13/16	9.25
14	350	20	1-1/8	8UN	1-13/16	10.00
16	400	20	1-1/4	8UN	2	11.00
18	450	24	1-1/4	8UN	2	11.50
20	500	24	1-1/4	8UN	2	12.50
24	600	24	1-1/2	8UN	2-3/8	14.50
Standard: ASME B16.47 Series A (MSS SP-44)
26	650	28	1-5/8	8UN	2-9/16	16.50
30	750	28	1-3/4	8UN	2-3/4	18.00
36	900	32	2	8UN	3-1/8	20.50
Standard: ASME B16.47 Series B (API 605) - Compact Flanges
26"	650	36	7/8"	UNC	1-7/16"	Calc*
30"	750	40	1"	8UN	1-5/8"	Calc*
36"	900	44	1"	8UN	1-5/8"	Calc*
42"	1050	48	1-1/8"	8UN	1-13/16"	Calc*
48"	1200	60	1-1/8"	8UN	1-13/16"	Calc*

Note: Bolt diameters above 1" are assumed to be 8UN pitch (ASTM A193 B7). Do not use UNC for large diameters unless specified by the flange manufacturer.

Calculation Basis: Lengths are estimated based on API 609 Category A Body Width + 2x Standard Flange Thickness + Gaskets + Nuts + 3 threads exposed.

Wafer Style: ASME Class 600 (High Pressure)

Standard: ASME B16.5

High pressure rating. Requires high-strength bolting (e.g., A193 B7).
Note: Diameters > 1" typically use 8UN thread pitch, not UNC.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (in)	DN (mm)	Qty	Diameter (in)	Thread Standard	Wrench Size (Heavy Hex)	Rec. Length (L) (in)
2"	50	8	5/8"	UNC	1-1/16"	Calc*
2.5"	65	8	3/4"	UNC	1-1/4"	Calc*
3"	80	8	3/4"	UNC	1-1/4"	Calc*
4"	100	8	7/8"	UNC	1-7/16"	Calc*
5"	125	8	1"	8UN	1-5/8"	Calc*
6"	150	12	1"	8UN	1-5/8"	Calc*
8"	200	12	1-1/8"	8UN	1-13/16"	Calc*
10"	250	16	1-1/4"	8UN	2"	Calc*
12"	300	20	1-1/4"	8UN	2"	Calc*
14"	350	20	1-3/8"	8UN	2-3/16"	Calc*
16"	400	20	1-1/2"	8UN	2-3/8"	Calc*
18"	450	20	1-5/8"	8UN	2-9/16"	Calc*
20"	500	24	1-5/8"	8UN	2-9/16"	Calc*
24"	600	24	1-7/8"	8UN	2-15/16"	Calc*
Standard: ASME B16.47 Series A (MSS SP-44)
26"	650	28	1-3/4"	8UN	2-3/4"	Calc*
28"	700	28	1-7/8"	8UN	2-15/16"	Calc*
30"	750	28	2"	8UN	3-1/8"	Calc*
32"	800	28	2"	8UN	3-1/8"	Calc*
36"	900	28	2-1/2"	8UN	3-7/8"	Calc*
42"	1050	28	2-3/4"	8UN	4-1/4"	Calc*
48"	1200	32	3"	8UN	4-5/8"	Calc*
Standard: ASME B16.47 Series B (API 605) - Compact Flanges
26"	650	28	1-1/4"	8UN	2"	Calc*
30"	750	28	1-3/8"	8UN	2-3/16"	Calc*
36"	900	28	1-5/8"	8UN	2-9/16"	Calc*
42"	1050	32	1-3/4"	8UN	2-3/4"	Calc*
48"	1200	40	1-7/8"	8UN	2-15/16"	Calc*

ASME Class 900 Wafer Valve Bolt Chart

High Pressure Applications (ASME B16.5)

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (in)	DN (mm)	Qty	Diameter (in)	Thread Standard	Wrench Size (Heavy Hex)	Rec. Length (L) (in)
Standard: ASME B16.5 (Limited Sizes for Wafer)
3	80	8	7/8	UNC	1-7/16	8.00
4	100	8	1-1/8	8UN	1-13/16	9.50
6	150	12	1-1/8	8UN	1-13/16	11.50
8	200	12	1-3/8	8UN	2-3/16	13.50
10	250	16	1-3/8	8UN	2-3/16	14.50
12	300	20	1-3/8	8UN	2-3/16	16.25
14	350	20	1-1/2	8UN	2-3/8	17.50
16	400	20	1-5/8	8UN	2-9/16	19.00
18	450	20	1-7/8	8UN	2-15/16	21.50
20	500	20	2	8UN	3-1/8	23.00
24	600	20	2-1/2	8UN	3-7/8	28.50
Standard: ASME B16.47 Series A (MSS SP-44) - Class 900
26"	650	20	2-3/4"	8UN	4-1/4"	Calc*
30"	750	20	3"	8UN	4-5/8"	Calc*
36"	900	20	3-1/2"	8UN	5-3/8"	Calc*
42"	1050	24	3-1/2"	8UN	5-3/8"	Calc*
48"	1200	24	4"	8UN	6-1/8"	Calc*
Standard: ASME B16.47 Series B (API 605) - Class 900
26"	650	24	1-3/4"	8UN	2-3/4"	Calc*
30"	750	24	2"	8UN	3-1/8"	Calc*
36"	900	28	2-1/4"	8UN	3-1/2"	Calc*
42"	1050	32	2-1/2"	8UN	3-7/8"	Calc*
48"	1200	40	2-1/2"	8UN	3-7/8"	Calc*

Critical Engineering Note:

Lug vs. Wafer: For Class 900 applications (especially above 12"), many engineers prefer Lug Style or Double Flanged valves. Long through-bolts in wafer installations can experience significant thermal expansion issues at high temperatures.
Sizes > 24": Data is not listed for sizes larger than 24" as Wafer style is extremely rare in Class 900 Large Diameter. Consult factory for Lug/Flanged data.
Length Calculation: Due to extreme flange thickness in Class 900, always double-check stud lengths against the specific valve drawing.

Wafer Style: EN 1092-1 PN 6

Engineering Note: PN 6

PN 6 is a low-pressure standard. Do not confuse M12/M16 bolts with higher pressure ratings. Wrench sizes are based on ISO 4032.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M12	ISO Metric	18	Calc*
2.5"	65	4	M12	ISO Metric	18	Calc*
3"	80	4	M16	ISO Metric	24	Calc*
4"	100	4	M16	ISO Metric	24	Calc*
5"	125	8	M16	ISO Metric	24	Calc*
6"	150	8	M16	ISO Metric	24	Calc*
8"	200	8	M16	ISO Metric	24	Calc*
10"	250	12	M16	ISO Metric	24	Calc*
12"	300	12	M20	ISO Metric	30	Calc*
14"	350	12	M20	ISO Metric	30	Calc*
16"	400	16	M20	ISO Metric	30	Calc*
18"	450	16	M20	ISO Metric	30	Calc*
20"	500	20	M20	ISO Metric	30	Calc*
24"	600	20	M24	ISO Metric	36	Calc*

Wafer Style: EN 1092-1 PN 10

Standard Note

Warning: DN 200 to DN 300 sizes differ significantly between PN 10 and PN 16. Verify flange pressure rating before installation.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	ISO Metric	24	Calc*
2.5"	65	4	M16	ISO Metric	24	Calc*
3"	80	8	M16	ISO Metric	24	Calc*
4"	100	8	M16	ISO Metric	24	Calc*
5"	125	8	M16	ISO Metric	24	Calc*
6"	150	8	M20	ISO Metric	30	Calc*
8"	200	8	M20	ISO Metric	30	Calc*
10"	250	12	M20	ISO Metric	30	Calc*
12"	300	12	M20	ISO Metric	30	Calc*
14"	350	16	M20	ISO Metric	30	Calc*
16"	400	16	M24	ISO Metric	36	Calc*
18"	450	20	M24	ISO Metric	36	Calc*
20"	500	20	M24	ISO Metric	36	Calc*
24"	600	20	M27	ISO Metric	41	Calc*

Wafer Style: EN 1092-1 PN 16

Standard Note

PN 16 is the most common industrial standard in Europe. Note the increased bolt count/size at DN 200+ compared to PN 10.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	ISO Metric	24	Calc*
2.5"	65	4	M16	ISO Metric	24	Calc*
3"	80	8	M16	ISO Metric	24	Calc*
4"	100	8	M16	ISO Metric	24	Calc*
5"	125	8	M16	ISO Metric	24	Calc*
6"	150	8	M20	ISO Metric	30	Calc*
8"	200	12	M20	ISO Metric	30	Calc*
10"	250	12	M24	ISO Metric	36	Calc*
12"	300	12	M24	ISO Metric	36	Calc*
14"	350	16	M24	ISO Metric	36	Calc*
16"	400	16	M27	ISO Metric	41	Calc*
18"	450	20	M27	ISO Metric	41	Calc*
20"	500	20	M30	ISO Metric	46	Calc*
24"	600	20	M33	ISO Metric	50	Calc*

Wafer Style: EN 1092-1 PN 25

Standard: EN 1092-1

Medium pressure. For sizes DN 50-150, the bolting pattern is often identical to PN 40, but check flange thickness.
Units: All diameters are Metric (mm).

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (ISO Hex)	Rec. Length (mm)
2"	50	4	M16	Metric ISO	24	Calc*
2.5"	65	8	M16	Metric ISO	24	Calc*
3"	80	8	M16	Metric ISO	24	Calc*
4"	100	8	M20	Metric ISO	30	Calc*
5"	125	8	M24	Metric ISO	36	Calc*
6"	150	8	M24	Metric ISO	36	Calc*
8"	200	12	M24	Metric ISO	36	Calc*
10"	250	12	M27	Metric ISO	41	Calc*
12"	300	16	M27	Metric ISO	41	Calc*
14"	350	16	M30	Metric ISO	46	Calc*
16"	400	16	M33	Metric ISO	50	Calc*
18"	450	20	M33	Metric ISO	50	Calc*
20"	500	20	M33	Metric ISO	50	Calc*
24"	600	20	M36	Metric ISO	55	Calc*

Wafer Style: EN 1092-1 PN 40

Standard Note

High pressure standard. Requires high-strength bolting (e.g., Grade 8.8 or higher). Ensure gaskets are rated for PN 40.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	ISO Metric	24	Calc*
2.5"	65	8	M16	ISO Metric	24	Calc*
3"	80	8	M16	ISO Metric	24	Calc*
4"	100	8	M20	ISO Metric	30	Calc*
5"	125	8	M24	ISO Metric	36	Calc*
6"	150	8	M24	ISO Metric	36	Calc*
8"	200	12	M27	ISO Metric	41	Calc*
10"	250	12	M30	ISO Metric	46	Calc*
12"	300	16	M30	ISO Metric	46	Calc*
14"	350	16	M33	ISO Metric	50	Calc*
16"	400	16	M36	ISO Metric	55	Calc*
18"	450	20	M36	ISO Metric	55	Calc*
20"	500	20	M39	ISO Metric	60	Calc*
24"	600	20	M45	ISO Metric	70	Calc*

Wafer Style: EN 1092-1 PN 63 (PN 64)

Standard Note

Standard designation is PN 63, but widely referred to as PN 64. Data is identical for both designations.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M20	ISO Metric	30	Calc*
2.5"	65	8	M20	ISO Metric	30	Calc*
3"	80	8	M20	ISO Metric	30	Calc*
4"	100	8	M24	ISO Metric	36	Calc*
5"	125	8	M27	ISO Metric	41	Calc*
6"	150	8	M30	ISO Metric	46	Calc*
8"	200	12	M33	ISO Metric	50	Calc*
10"	250	12	M36	ISO Metric	55	Calc*
12"	300	16	M36	ISO Metric	55	Calc*
14"	350	16	M39	ISO Metric	60	Calc*
16"	400	16	M45	ISO Metric	70	Calc*
18"	450	20	M45	ISO Metric	70	Calc*
20"	500	20	M48	ISO Metric	75	Calc*
24"	600	20	M52	ISO Metric	80	Calc*

* Important Note on Bolt Lengths

Rec. Length is listed as "Calc*" (Calculate) because European wafer valves (EN 558) come in multiple Face-to-Face standards (Series 20, Series 16, Series 13).
Formula: Bolt Length = Valve Face-to-Face + 2x Flange Thickness + 2x Gasket + 2x Nut Height + ~10mm Extra.

Wafer Style: EN 1092-1 PN 100

Standard: EN 1092-1 (High Pressure)

Very high pressure rating. Bolts are significantly larger. Ensure valve body width allows for clearance of these large nuts.
Note: Data limited to DN 500 as per common wafer valve availability.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (ISO Hex)	Rec. Length (mm)
2"	50	4	M20	Metric ISO	30	Calc*
2.5"	65	8	M24	Metric ISO	36	Calc*
3"	80	8	M24	Metric ISO	36	Calc*
4"	100	8	M27	Metric ISO	41	Calc*
5"	125	8	M30	Metric ISO	46	Calc*
6"	150	12	M30	Metric ISO	46	Calc*
8"	200	12	M33	Metric ISO	50	Calc*
10"	250	12	M36	Metric ISO	55	Calc*
12"	300	16	M36	Metric ISO	55	Calc*
14"	350	16	M39	Metric ISO	60	Calc*
16"	400	16	M45	Metric ISO	70	Calc*
18"	450	20	M45	Metric ISO	70	Calc*
20"	500	20	M52	Metric ISO	80	Calc*

Wafer Style: DIN PN 6 (DIN 2631)

Standard Note: DIN 2501 / 2631

Legacy German standard for low pressure. Often interchangeable with EN 1092-1 PN 6. Uses ISO metric coarse threads.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M12	DIN Metric	18/19*	Calc*
2.5"	65	4	M12	DIN Metric	18/19*	Calc*
3"	80	4	M16	DIN Metric	24	Calc*
4"	100	4	M16	DIN Metric	24	Calc*
5"	125	8	M16	DIN Metric	24	Calc*
6"	150	8	M16	DIN Metric	24	Calc*
8"	200	8	M16	DIN Metric	24	Calc*
10"	250	12	M16	DIN Metric	24	Calc*
12"	300	12	M20	DIN Metric	30	Calc*
14"	350	12	M20	DIN Metric	30	Calc*
16"	400	16	M20	DIN Metric	30	Calc*
18"	450	16	M20	DIN Metric	30	Calc*
20"	500	20	M20	DIN Metric	30	Calc*
24"	600	20	M24	DIN Metric	36	Calc*

Wafer Style: DIN PN 10 (DIN 2632)

Standard Note

Critical Difference: At DN 200 and above, bolt quantities differ significantly from PN 16. Ensure the mating flanges are stamped PN 10.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	DIN Metric	24	Calc*
2.5"	65	4	M16	DIN Metric	24	Calc*
3"	80	8	M16	DIN Metric	24	Calc*
4"	100	8	M16	DIN Metric	24	Calc*
5"	125	8	M16	DIN Metric	24	Calc*
6"	150	8	M20	DIN Metric	30	Calc*
8"	200	8	M20	DIN Metric	30	Calc*
10"	250	12	M20	DIN Metric	30	Calc*
12"	300	12	M20	DIN Metric	30	Calc*
14"	350	16	M20	DIN Metric	30	Calc*
16"	400	16	M24	DIN Metric	36	Calc*
18"	450	20	M24	DIN Metric	36	Calc*
20"	500	20	M24	DIN Metric	36	Calc*
24"	600	20	M27	DIN Metric	41	Calc*

Wafer Style: DIN PN 16 (DIN 2633)

Standard Note

This is the most common DIN standard. Note that M24 bolts are used starting at DN 250 (unlike PN 10 which uses M20 there).

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	DIN Metric	24	Calc*
2.5"	65	4	M16	DIN Metric	24	Calc*
3"	80	8	M16	DIN Metric	24	Calc*
4"	100	8	M16	DIN Metric	24	Calc*
5"	125	8	M16	DIN Metric	24	Calc*
6"	150	8	M20	DIN Metric	30	Calc*
8"	200	12	M20	DIN Metric	30	Calc*
10"	250	12	M24	DIN Metric	36	Calc*
12"	300	12	M24	DIN Metric	36	Calc*
14"	350	16	M24	DIN Metric	36	Calc*
16"	400	16	M27	DIN Metric	41	Calc*
18"	450	20	M27	DIN Metric	41	Calc*
20"	500	20	M30	DIN Metric	46	Calc*
24"	600	20	M33	DIN Metric	50	Calc*

Wafer Style: DIN PN 25

Standard: DIN 2634

Specific German standard for PN 25. Distinct from PN 16 and PN 40 in larger sizes.
Note: Wrench sizes listed are for standard DIN 934 nuts.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	DIN Metric	24	Calc*
2.5"	65	8	M16	DIN Metric	24	Calc*
3"	80	8	M16	DIN Metric	24	Calc*
4"	100	8	M20	DIN Metric	30	Calc*
5"	125	8	M24	DIN Metric	36	Calc*
6"	150	8	M24	DIN Metric	36	Calc*
8"	200	12	M24	DIN Metric	36	Calc*
10"	250	12	M27	DIN Metric	41	Calc*
12"	300	16	M27	DIN Metric	41	Calc*
14"	350	16	M30	DIN Metric	46	Calc*
16"	400	16	M33	DIN Metric	50	Calc*
20"	500	20	M33	DIN Metric	50	Calc*
24"	600	20	M36	DIN Metric	55	Calc*

Wafer Style: DIN PN 40 (DIN 2635)

Standard Note

Heavy duty standard. Often used for steam or high-pressure process lines. Bolt diameters increase rapidly as the valve size grows.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	DIN Metric	24	Calc*
2.5"	65	8	M16	DIN Metric	24	Calc*
3"	80	8	M16	DIN Metric	24	Calc*
4"	100	8	M20	DIN Metric	30	Calc*
5"	125	8	M24	DIN Metric	36	Calc*
6"	150	8	M24	DIN Metric	36	Calc*
8"	200	12	M27	DIN Metric	41	Calc*
10"	250	12	M30	DIN Metric	46	Calc*
12"	300	16	M30	DIN Metric	46	Calc*
14"	350	16	M33	DIN Metric	50	Calc*
16"	400	16	M36	DIN Metric	55	Calc*
18"	450	20	M36	DIN Metric	55	Calc*
20"	500	20	M39	DIN Metric	60	Calc*
24"	600	20	M45	DIN Metric	70	Calc*

Wafer Style: DIN PN 64 (DIN 2636)

Standard Note

In the DIN standard, this pressure class is designated as PN 64 (equivalent to EN PN 63). It is used for very high-pressure applications.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M20	DIN Metric	30	Calc*
2.5"	65	8	M20	DIN Metric	30	Calc*
3"	80	8	M20	DIN Metric	30	Calc*
4"	100	8	M24	DIN Metric	36	Calc*
5"	125	8	M27	DIN Metric	41	Calc*
6"	150	8	M30	DIN Metric	46	Calc*
8"	200	12	M33	DIN Metric	50	Calc*
10"	250	12	M36	DIN Metric	55	Calc*
12"	300	16	M36	DIN Metric	55	Calc*
14"	350	16	M39	DIN Metric	60	Calc*
16"	400	16	M45	DIN Metric	70	Calc*
18"	450	20	M45	DIN Metric	70	Calc*
20"	500	20	M48	DIN Metric	75	Calc*
24"	600	20	M52	DIN Metric	80	Calc*

* Wrench Size Note

Old DIN 931/933 standards used different wrench sizes for M10/M12 compared to modern ISO standards. The values listed above reflect the modern ISO standard (which most new bolts follow), but verify your specific bolt head size.

Wafer Style: DIN PN 100 (Very High Pressure)

Standard: DIN 2637

Highest common DIN rating for wafer valves. Flanges are extremely thick.
Limitation: Data provided up to DN 400. Sizes above this usually require double-flanged bodies.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M24	DIN Metric	36	Calc*
2.5"	65	8	M24	DIN Metric	36	Calc*
3"	80	8	M24	DIN Metric	36	Calc*
4"	100	8	M27	DIN Metric	41	Calc*
5"	125	8	M30	DIN Metric	46	Calc*
6"	150	12	M30	DIN Metric	46	Calc*
8"	200	12	M33	DIN Metric	50	Calc*
10"	250	12	M36	DIN Metric	55	Calc*
12"	300	16	M39	DIN Metric	60	Calc*
14"	350	16	M45	DIN Metric	70	Calc*
16"	400	16	M52	DIN Metric	80	Calc*

Wafer Style: BS 4504 PN 6 (Metric)

Standard Note: BS 4504

This is the British Metric standard. It is effectively identical to DIN 2501 and EN 1092-1 for these sizes. Use metric bolting (M-Thread).

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M12	BS Metric	18/19	Calc*
2.5"	65	4	M12	BS Metric	18/19	Calc*
3"	80	4	M16	BS Metric	24	Calc*
4"	100	4	M16	BS Metric	24	Calc*
5"	125	8	M16	BS Metric	24	Calc*
6"	150	8	M16	BS Metric	24	Calc*
8"	200	8	M16	BS Metric	24	Calc*
10"	250	12	M16	BS Metric	24	Calc*
12"	300	12	M20	BS Metric	30	Calc*
14"	350	12	M20	BS Metric	30	Calc*
16"	400	16	M20	BS Metric	30	Calc*
18"	450	16	M20	BS Metric	30	Calc*
20"	500	20	M20	BS Metric	30	Calc*
24"	600	20	M24	BS Metric	36	Calc*

Wafer Style: BS 4504 PN 10 (Metric)

Standard Note

Warning: Do not confuse BS 4504 PN 10 with BS 10 Table D/E. They are completely different. This table is for Metric PN 10 flanges.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	BS Metric	24	Calc*
2.5"	65	4	M16	BS Metric	24	Calc*
3"	80	8	M16	BS Metric	24	Calc*
4"	100	8	M16	BS Metric	24	Calc*
5"	125	8	M16	BS Metric	24	Calc*
6"	150	8	M20	BS Metric	30	Calc*
8"	200	8	M20	BS Metric	30	Calc*
10"	250	12	M20	BS Metric	30	Calc*
12"	300	12	M20	BS Metric	30	Calc*
14"	350	16	M20	BS Metric	30	Calc*
16"	400	16	M24	BS Metric	36	Calc*
18"	450	20	M24	BS Metric	36	Calc*
20"	500	20	M24	BS Metric	36	Calc*
24"	600	20	M27	BS Metric	41	Calc*

Wafer Style: BS 4504 PN 16 (Metric)

Standard Note

PN 16 is the standard industrial pressure class in the UK for water and general industry. M24 bolts are used from DN 250 upwards.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	BS Metric	24	Calc*
2.5"	65	4	M16	BS Metric	24	Calc*
3"	80	8	M16	BS Metric	24	Calc*
4"	100	8	M16	BS Metric	24	Calc*
5"	125	8	M16	BS Metric	24	Calc*
6"	150	8	M20	BS Metric	30	Calc*
8"	200	12	M20	BS Metric	30	Calc*
10"	250	12	M24	BS Metric	36	Calc*
12"	300	12	M24	BS Metric	36	Calc*
14"	350	16	M24	BS Metric	36	Calc*
16"	400	16	M27	BS Metric	41	Calc*
18"	450	20	M27	BS Metric	41	Calc*
20"	500	20	M30	BS Metric	46	Calc*
24"	600	20	M33	BS Metric	50	Calc*

Wafer Style: BS 4504 PN 40 (Metric)

Standard Note

BS 4504 PN 40 requires high-strength bolting. Dimensions align with EN 1092-1 PN 40.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	BS Metric	24	Calc*
2.5"	65	8	M16	BS Metric	24	Calc*
3"	80	8	M16	BS Metric	24	Calc*
4"	100	8	M20	BS Metric	30	Calc*
5"	125	8	M24	BS Metric	36	Calc*
6"	150	8	M24	BS Metric	36	Calc*
8"	200	12	M27	BS Metric	41	Calc*
10"	250	12	M30	BS Metric	46	Calc*
12"	300	16	M30	BS Metric	46	Calc*
14"	350	16	M33	BS Metric	50	Calc*
16"	400	16	M36	BS Metric	55	Calc*
18"	450	20	M36	BS Metric	55	Calc*
20"	500	20	M39	BS Metric	60	Calc*
24"	600	20	M45	BS Metric	70	Calc*

Wafer Style: BS 4504 PN 64 (Metric)

Standard Note

In BS 4504, this class is designated PN 64. It corresponds to PN 63 in newer European Norms. Use very high strength bolting (e.g., Grade 10.9).

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M20	BS Metric	30	Calc*
2.5"	65	8	M20	BS Metric	30	Calc*
3"	80	8	M20	BS Metric	30	Calc*
4"	100	8	M24	BS Metric	36	Calc*
5"	125	8	M27	BS Metric	41	Calc*
6"	150	8	M30	BS Metric	46	Calc*
8"	200	12	M33	BS Metric	50	Calc*
10"	250	12	M36	BS Metric	55	Calc*
12"	300	16	M36	BS Metric	55	Calc*
14"	350	16	M39	BS Metric	60	Calc*
16"	400	16	M45	BS Metric	70	Calc*
18"	450	20	M45	BS Metric	70	Calc*
20"	500	20	M48	BS Metric	75	Calc*
24"	600	20	M52	BS Metric	80	Calc*

Wafer Style: JIS 5K Flanges

Standard Note: JIS B 2220 5K

JIS 5K is a light-duty standard commonly used in utility water and low-pressure drainage. Bolt diameters are small compared to international equivalents.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M10	JIS Metric	17	Calc*
2.5"	65	4	M10	JIS Metric	17	Calc*
3"	80	4	M12	JIS Metric	19	Calc*
4"	100	8	M12	JIS Metric	19	Calc*
5"	125	8	M12	JIS Metric	19	Calc*
6"	150	8	M12	JIS Metric	19	Calc*
8"	200	8	M16	JIS Metric	24	Calc*
10"	250	12	M16	JIS Metric	24	Calc*
12"	300	12	M16	JIS Metric	24	Calc*
14"	350	12	M20	JIS Metric	30	Calc*
16"	400	16	M20	JIS Metric	30	Calc*
18"	450	16	M20	JIS Metric	30	Calc*
20"	500	20	M20	JIS Metric	30	Calc*
24"	600	20	M24	JIS Metric	36	Calc*

Wafer Style: JIS 10K Flanges

Standard Note: JIS B 2220 10K

JIS 10K is the most common industrial pressure rating in Japan and Asia. Note the use of M22 bolts in larger sizes, which are uncommon in other standards.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	JIS Metric	24	Calc*
2.5"	65	4	M16	JIS Metric	24	Calc*
3"	80	8	M16	JIS Metric	24	Calc*
4"	100	8	M16	JIS Metric	24	Calc*
5"	125	8	M20	JIS Metric	30	Calc*
6"	150	8	M20	JIS Metric	30	Calc*
8"	200	12	M20	JIS Metric	30	Calc*
10"	250	12	M22	JIS Metric	32	Calc*
12"	300	16	M22	JIS Metric	32	Calc*
14"	350	16	M22	JIS Metric	32	Calc*
16"	400	16	M24	JIS Metric	36	Calc*
18"	450	20	M24	JIS Metric	36	Calc*
20"	500	20	M24	JIS Metric	36	Calc*
24"	600	24	M30	JIS Metric	46	Calc*

Wafer Style: JIS 16K Flanges

Standard Note: JIS B 2220 16K

16K is an intermediate pressure class. It is less common than 10K or 20K but frequently found in marine and stationary machinery applications.

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	8	M16	JIS Metric	24	Calc*
2.5"	65	8	M16	JIS Metric	24	Calc*
3"	80	8	M20	JIS Metric	30	Calc*
4"	100	8	M20	JIS Metric	30	Calc*
5"	125	8	M22	JIS Metric	32	Calc*
6"	150	12	M22	JIS Metric	32	Calc*
8"	200	12	M22	JIS Metric	32	Calc*
10"	250	12	M24	JIS Metric	36	Calc*
12"	300	16	M24	JIS Metric	36	Calc*
14"	350	16	M30	JIS Metric	46	Calc*
16"	400	16	M30	JIS Metric	46	Calc*
18"	450	20	M30	JIS Metric	46	Calc*
20"	500	20	M30	JIS Metric	46	Calc*
24"	600	20	M36	JIS Metric	55	Calc*

Wafer Style: JIS 20K Flanges

Standard Note: JIS B 2220 20K

JIS 20K is a high-pressure standard roughly equivalent to ASME Class 300. It requires larger bolting diameters and high-strength materials (e.g., SNB7).

Valve Size		Bolting Hardware (Studs or Hex Bolts)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	8	M16	JIS Metric	24	Calc*
2.5"	65	8	M16	JIS Metric	24	Calc*
3"	80	8	M20	JIS Metric	30	Calc*
4"	100	8	M20	JIS Metric	30	Calc*
5"	125	8	M22	JIS Metric	32	Calc*
6"	150	12	M22	JIS Metric	32	Calc*
8"	200	12	M22	JIS Metric	32	Calc*
10"	250	12	M24	JIS Metric	36	Calc*
12"	300	16	M24	JIS Metric	36	Calc*
14"	350	16	M30	JIS Metric	46	Calc*
16"	400	16	M30	JIS Metric	46	Calc*
18"	450	20	M30	JIS Metric	46	Calc*
20"	500	20	M30	JIS Metric	46	Calc*
24"	600	20	M36	JIS Metric	55	Calc*

* Calculation Note for JIS Wafer Valves

Bolt lengths are marked as Calc* because JIS wafer valves vary significantly in face-to-face dimensions between manufacturers.
Calculation: (Valve Body Width) + 2x(Flange Thickness per JIS B 2220) + 2x(Gasket) + 2x(Nut) + Extra.

Wafer Style: AS 2129 Table D

Standard Note: Table D

Commonly used for water services and irrigation. Low pressure. Uses Imperial sized bolts (BSW/UNC) on Metric pipe sizes.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (in)	DN (mm)	Qty	Diameter (in)	Thread Standard	Wrench Size (BSW Hex)	Rec. Length (L) (in)
2"	50	4	5/8"	BSW / UNC	1.01"	Calc*
2.5"	65	4	5/8"	BSW / UNC	1.01"	Calc*
3"	80	4	5/8"	BSW / UNC	1.01"	Calc*
4"	100	4	5/8"	BSW / UNC	1.01"	Calc*
5"	125	8	5/8"	BSW / UNC	1.01"	Calc*
6"	150	8	5/8"	BSW / UNC	1.01"	Calc*
8"	200	8	5/8"	BSW / UNC	1.01"	Calc*
10"	250	8	3/4"	BSW / UNC	1.20"	Calc*
12"	300	12	3/4"	BSW / UNC	1.20"	Calc*
14"	350	12	7/8"	BSW / UNC	1.30"	Calc*
16"	400	12	7/8"	BSW / UNC	1.30"	Calc*
18"	450	12	1"	BSW / UNC	1.48"	Calc*
20"	500	16	1"	BSW / UNC	1.48"	Calc*
24"	600	16	1-1/8"	BSW / UNC	1.67"	Calc*

Wafer Style: AS 2129 Table E

Standard Note: Table E

The most common historic Australian standard for general industry. Note: 4" (DN100) has 8 bolts in Table E, but only 4 bolts in Table D.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (in)	DN (mm)	Qty	Diameter (in)	Thread Standard	Wrench Size (BSW Hex)	Rec. Length (L) (in)
2"	50	4	5/8"	BSW / UNC	1.01"	Calc*
2.5"	65	4	5/8"	BSW / UNC	1.01"	Calc*
3"	80	4	5/8"	BSW / UNC	1.01"	Calc*
4"	100	8	5/8"	BSW / UNC	1.01"	Calc*
5"	125	8	5/8"	BSW / UNC	1.01"	Calc*
6"	150	8	3/4"	BSW / UNC	1.20"	Calc*
8"	200	8	3/4"	BSW / UNC	1.20"	Calc*
10"	250	12	3/4"	BSW / UNC	1.20"	Calc*
12"	300	12	7/8"	BSW / UNC	1.30"	Calc*
14"	350	12	1"	BSW / UNC	1.48"	Calc*
16"	400	12	1"	BSW / UNC	1.48"	Calc*
18"	450	16	1"	BSW / UNC	1.48"	Calc*
20"	500	16	1"	BSW / UNC	1.48"	Calc*
24"	600	16	1-1/4"	BSW / UNC	1.86"	Calc*

Wafer Style: AS 2129 Table F

Standard Note: Table F

Used for higher pressure applications than Table E. Bolt diameters increase significantly.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (in)	DN (mm)	Qty	Diameter (in)	Thread Standard	Wrench Size (BSW Hex)	Rec. Length (L) (in)
2"	50	4	5/8"	BSW / UNC	1.01"	Calc*
2.5"	65	8	5/8"	BSW / UNC	1.01"	Calc*
3"	80	8	5/8"	BSW / UNC	1.01"	Calc*
4"	100	8	3/4"	BSW / UNC	1.20"	Calc*
5"	125	8	7/8"	BSW / UNC	1.30"	Calc*
6"	150	12	7/8"	BSW / UNC	1.30"	Calc*
8"	200	12	1"	BSW / UNC	1.48"	Calc*
10"	250	12	1-1/8"	BSW / UNC	1.67"	Calc*
12"	300	16	1-1/8"	BSW / UNC	1.67"	Calc*
14"	350	16	1-1/4"	BSW / UNC	1.86"	Calc*
16"	400	20	1-1/4"	BSW / UNC	1.86"	Calc*
18"	450	20	1-3/8"	BSW / UNC	2.05"	Calc*
20"	500	24	1-1/2"	BSW / UNC	2.22"	Calc*
24"	600	24	1-5/8"	BSW / UNC	2.41"	Calc*

Wafer Style: AS 2129 Table H

Standard Note: Table H

High pressure standard. Often comparable to Class 300 or PN 40 in terms of application severity.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (in)	DN (mm)	Qty	Diameter (in)	Thread Standard	Wrench Size (BSW Hex)	Rec. Length (L) (in)
2"	50	8	5/8"	BSW / UNC	1.01"	Calc*
2.5"	65	8	5/8"	BSW / UNC	1.01"	Calc*
3"	80	8	5/8"	BSW / UNC	1.01"	Calc*
4"	100	8	3/4"	BSW / UNC	1.20"	Calc*
5"	125	12	3/4"	BSW / UNC	1.20"	Calc*
6"	150	12	7/8"	BSW / UNC	1.30"	Calc*
8"	200	12	7/8"	BSW / UNC	1.30"	Calc*
10"	250	12	1"	BSW / UNC	1.48"	Calc*
12"	300	16	1-1/8"	BSW / UNC	1.67"	Calc*
14"	350	16	1-1/4"	BSW / UNC	1.86"	Calc*
16"	400	20	1-1/4"	BSW / UNC	1.86"	Calc*
18"	450	20	1-3/8"	BSW / UNC	2.05"	Calc*
20"	500	24	1-1/2"	BSW / UNC	2.22"	Calc*
24"	600	24	1-3/4"	BSW / UNC	2.58"	Calc*

Wafer Style: GOST PN 6

Standard: GOST 33259-2015

Current Russian standard. Dimensions for PN 6 are generally compatible with DIN/EN PN 6. Use GOST/ISO Metric bolts.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M12	GOST Metric	18/19	Calc*
2.5"	65	4	M12	GOST Metric	18/19	Calc*
3"	80	4	M16	GOST Metric	24	Calc*
4"	100	4	M16	GOST Metric	24	Calc*
5"	125	8	M16	GOST Metric	24	Calc*
6"	150	8	M16	GOST Metric	24	Calc*
8"	200	8	M16	GOST Metric	24	Calc*
10"	250	12	M16	GOST Metric	24	Calc*
12"	300	12	M20	GOST Metric	30	Calc*
14"	350	12	M20	GOST Metric	30	Calc*
16"	400	16	M20	GOST Metric	30	Calc*
20"	500	20	M20	GOST Metric	30	Calc*
24"	600	20	M24	GOST Metric	36	Calc*

Wafer Style: GOST PN 10

Standard Note

Standard low-pressure piping in Russia/EAEU. Verify exact flange thickness (Type 01 vs Type 11) for bolt length calculation.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	GOST Metric	24	Calc*
2.5"	65	4	M16	GOST Metric	24	Calc*
3"	80	8	M16	GOST Metric	24	Calc*
4"	100	8	M16	GOST Metric	24	Calc*
5"	125	8	M16	GOST Metric	24	Calc*
6"	150	8	M20	GOST Metric	30	Calc*
8"	200	8	M20	GOST Metric	30	Calc*
10"	250	12	M20	GOST Metric	30	Calc*
12"	300	12	M20	GOST Metric	30	Calc*
14"	350	16	M20	GOST Metric	30	Calc*
16"	400	16	M24	GOST Metric	36	Calc*
20"	500	20	M24	GOST Metric	36	Calc*
24"	600	20	M27	GOST Metric	41	Calc*

Wafer Style: GOST PN 16

Standard Note

Most common industrial rating. M24 bolts start at DN 250.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	GOST Metric	24	Calc*
2.5"	65	4	M16	GOST Metric	24	Calc*
3"	80	8	M16	GOST Metric	24	Calc*
4"	100	8	M16	GOST Metric	24	Calc*
5"	125	8	M16	GOST Metric	24	Calc*
6"	150	8	M20	GOST Metric	30	Calc*
8"	200	12	M20	GOST Metric	30	Calc*
10"	250	12	M24	GOST Metric	36	Calc*
12"	300	12	M24	GOST Metric	36	Calc*
14"	350	16	M24	GOST Metric	36	Calc*
16"	400	16	M27	GOST Metric	41	Calc*
20"	500	20	M30	GOST Metric	46	Calc*
24"	600	20	M33	GOST Metric	50	Calc*

Wafer Style: GOST PN 25

Standard Note: PN 25

PN 25 is a specific pressure class in GOST (unlike ASME). It sits between PN 16 and PN 40. Dimensions are unique.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	GOST Metric	24	Calc*
2.5"	65	8	M16	GOST Metric	24	Calc*
3"	80	8	M16	GOST Metric	24	Calc*
4"	100	8	M20	GOST Metric	30	Calc*
5"	125	8	M24	GOST Metric	36	Calc*
6"	150	8	M24	GOST Metric	36	Calc*
8"	200	12	M24	GOST Metric	36	Calc*
10"	250	12	M27	GOST Metric	41	Calc*
12"	300	16	M27	GOST Metric	41	Calc*
14"	350	16	M30	GOST Metric	46	Calc*
16"	400	16	M33	GOST Metric	50	Calc*
20"	500	20	M33	GOST Metric	50	Calc*
24"	600	20	M39	GOST Metric	60	Calc*

Wafer Style: GOST PN 40

Standard Note

High Pressure. Comparable to ASME Class 300 in pressure rating.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M16	GOST Metric	24	Calc*
2.5"	65	8	M16	GOST Metric	24	Calc*
3"	80	8	M16	GOST Metric	24	Calc*
4"	100	8	M20	GOST Metric	30	Calc*
5"	125	8	M24	GOST Metric	36	Calc*
6"	150	8	M24	GOST Metric	36	Calc*
8"	200	12	M27	GOST Metric	41	Calc*
10"	250	12	M30	GOST Metric	46	Calc*
12"	300	16	M30	GOST Metric	46	Calc*
14"	350	16	M33	GOST Metric	50	Calc*
16"	400	16	M39	GOST Metric	60	Calc*
20"	500	20	M45	GOST Metric	70	Calc*
24"	600	20	M52	GOST Metric	80	Calc*

Wafer Style: GOST PN 63

Standard Note: PN 63

Designated as PN 63 in GOST (sometimes referred to as PN 64 in trade). Requires high strength bolting (e.g., Grade 10.9 or higher).

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M20	GOST Metric	30	Calc*
2.5"	65	8	M20	GOST Metric	30	Calc*
3"	80	8	M20	GOST Metric	30	Calc*
4"	100	8	M24	GOST Metric	36	Calc*
5"	125	8	M27	GOST Metric	41	Calc*
6"	150	8	M30	GOST Metric	46	Calc*
8"	200	12	M33	GOST Metric	50	Calc*
10"	250	12	M36	GOST Metric	55	Calc*
12"	300	16	M36	GOST Metric	55	Calc*
16"	400	16	M45	GOST Metric	70	Calc*
20"	500	20	M52	GOST Metric	80	Calc*
24"	600	20	M56	GOST Metric	85	Calc*

Wafer Style: GOST PN 100

Standard Note: PN 100

Very High Pressure. Ensure valve body and flange materials are rated for this pressure class.

Valve Size		Bolting Hardware (Studs)				Ref. Length
NPS (approx)	DN (mm)	Qty	Diameter (Metric)	Thread Standard	Wrench Size (mm)	Rec. Length (mm)
2"	50	4	M24	GOST Metric	36	Calc*
2.5"	65	8	M24	GOST Metric	36	Calc*
3"	80	8	M24	GOST Metric	36	Calc*
4"	100	8	M27	GOST Metric	41	Calc*
5"	125	8	M30	GOST Metric	46	Calc*
6"	150	8	M33	GOST Metric	50	Calc*
8"	200	12	M39	GOST Metric	60	Calc*
10"	250	12	M45	GOST Metric	70	Calc*
12"	300	16	M45	GOST Metric	70	Calc*
16"	400	16	M52	GOST Metric	80	Calc*

Lug Style Butterfly Valve Bolt Chart

Data below represents the required Cap Screws for Lug Style valves. The quantity is double the flange bolt hole count, as each flange is bolted to the valve body independently. Ensure cap screw length is appropriate for the flange thickness and thread engagement.

ASME Class 150 (and Class 125) Lug Valve Bolt Chart

CRITICAL INSTALLATION NOTE: Lug valves are bolted from both sides. The quantities below represent the TOTAL number of Cap Screws required for one valve (installing two flanges).

Valve Size		Bolting Hardware (Cap Screws / Hex Bolts)
NPS (in)	DN (mm)	Total Qty (Both Sides)	Diameter (in)	Thread Pitch (TPI)	Ref. Flange Thickness (in)	Calc. Length (L)* (Min. Ref Only)
Standard: ASME B16.1 / B16.5 (Up to 24")
2	50	8	5/8	11 (UNC)	0.75	1.75
2.5	65	8	5/8	11 (UNC)	0.88	1.75
3	80	8	5/8	11 (UNC)	0.94	2.00
4	100	16	5/8	11 (UNC)	0.94	2.00
5	125	16	3/4	10 (UNC)	0.94	2.25
6	150	16	3/4	10 (UNC)	1.00	2.25
8	200	16	3/4	10 (UNC)	1.12	2.50
10	250	24	7/8	9 (UNC)	1.19	2.75
12	300	24	7/8	9 (UNC)	1.25	3.00
14	350	24	1	8 (UNC)*	1.38	3.25
16	400	32	1	8 (UNC)*	1.44	3.25
18	450	32	1-1/8	7 or 8*	1.56	3.50
20	500	40	1-1/8	7 or 8*	1.69	3.75
24	600	40	1-1/4	7 or 8*	1.88	4.25
Standard: ASME B16.47 Series A (NPS 26+)
26	650	48	1-1/4	8UN	2.00*	Calc Req.
30	750	56	1-1/4	8UN	2.12*	Calc Req.
36	900	64	1-1/2	8UN	2.38*	Calc Req.

* Data Source & Calculation Logic (Transparency Note):

Class 125 vs 150: Sizes 2" through 24" share the same drilling template (Bolt Circle & Hole Qty) for ASME B16.1 (Cast Iron) and ASME B16.5 (Steel).
Length Calculation: No single standard defines Lug Bolt Length. The "Calc. Length" above is estimated using:
Length = Flange Thickness + Gasket(0.125") + Washer(0.125") + 1.0x Bolt Diameter (Engagement).
Rounded up to the nearest 0.25".
Thread Pitch Warning (NPS 14"+):
- Ductile Iron Valves (Class 125): Typically use UNC (Coarse) threads for all sizes.
- Steel Valves (Class 150): Typically use 8UN (8 thread series) for bolts > 1".
- Action: You MUST measure the thread pitch of the physical valve before ordering bolts for sizes 14" and larger.

ASME Class 300 Lug Valve Bolt Chart

Installation: Quantities listed are the TOTAL Cap Screws required for one valve (installing two flanges).

Valve Size		Bolting Hardware (Lug Cap Screws)
NPS (in)	DN (mm)	Total Qty (Both Sides)	Diameter (in)	Thread Standard	Ref. Flange Thickness (in)	Calc. Length (L)* (Min. Ref)
2	50	16	5/8	UNC	0.88	2.00
2.5	65	16	3/4	UNC	1.00	2.25
3	80	16	3/4	UNC	1.12	2.50
4	100	16	3/4	UNC	1.25	2.50
6	150	24	3/4	UNC	1.44	2.75
8	200	24	7/8	UNC	1.62	3.00
10	250	32	1	8UN	1.88	3.50
12	300	32	1-1/8	8UN	2.00	3.75
14	350	40	1-1/8	8UN	2.12	4.00
16	400	40	1-1/4	8UN	2.25	4.25
18	450	48	1-1/4	8UN	2.38	4.50
20	500	48	1-1/4	8UN	2.50	4.75
24	600	48	1-1/2	8UN	2.75	5.25

* Class 300 Calculation Formula:

Length = Flange Thickness (Inc. 1/16" RF) + Gasket/Washer (0.25") + 1.0x Bolt Diameter (Engagement).

ASME Class 600 Lug Valve Bolt Chart

RF Face Warning: Class 600 Flanges typically have a 1/4" (6.4mm) Raised Face which is ADDITIONAL to the minimum flange thickness.

Valve Size		Bolting Hardware (Lug Cap Screws)
NPS (in)	DN (mm)	Total Qty (Both Sides)	Diameter (in)	Thread Standard	Ref. Flange Thickness (in)	Calc. Length (L)* (Min. Ref)
2	50	16	5/8	UNC	1.00	2.25
3	80	16	3/4	UNC	1.25	2.75
4	100	16	7/8	UNC	1.50	3.25
6	150	24	1	8UN	1.88	3.75
8	200	24	1-1/8	8UN	2.19	4.25
10	250	32	1-1/4	8UN	2.50	4.75
12	300	40	1-1/4	8UN	2.62	5.00
14	350	40	1-3/8	8UN	2.75	5.25
16	400	40	1-1/2	8UN	3.00	5.75
18	450	40	1-5/8	8UN	3.25	6.00
20	500	48	1-5/8	8UN	3.50	6.25
24	600	48	1-7/8	8UN	4.00	7.25

* Class 600 Calculation Formula:

Length = Base Flange Thickness + 0.25" RF Height + Gasket/Washer (0.25") + 1.0x Bolt Diameter (Engagement).

ASME Class 900 Lug Valve Bolt Chart

Warning: Class 900 valves are typically High-Performance Offset designs. Body geometry and thread depth vary significantly by manufacturer.

Valve Size		Bolting Hardware (Lug Cap Screws)
NPS (in)	DN (mm)	Total Qty (Both Sides)	Diameter (in)	Thread Standard	Ref. Flange Thickness (in)	Length (L)
3	80	16	7/8	UNC	1.50	Check Mfg
4	100	16	1-1/8	8UN	1.75	Check Mfg
6	150	24	1-1/8	8UN	2.19	Check Mfg
8	200	24	1-3/8	8UN	2.50	Check Mfg
10	250	32	1-3/8	8UN	2.75	Check Mfg
12	300	40	1-3/8	8UN	3.12	Check Mfg
14	350	40	1-1/2	8UN	3.38	Check Mfg
16	400	40	1-5/8	8UN	3.50	Check Mfg
18	450	40	1-7/8	8UN	4.00	Check Mfg
20	500	40	2	8UN	4.25	Check Mfg
24	600	40	2-1/2	8UN	5.50	Check Mfg

* Why is Length Missing?

Class 900 flanges have a 0.25" Raised Face. However, the thread depth in the valve body is not standardized by API 609 for Class 900. Estimating length here risks bottoming out the bolt or insufficient engagement. Please measure the physical valve.

EN 1092-1 PN6 Lug Valve Bolt Chart

Metric Hardware: Use Metric (ISO) coarse thread bolts. Quantities are TOTAL per valve (both sides).

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M12 x 1.75	14	35
2.5	65	8	M12 x 1.75	14	35
3	80	8	M16 x 2.0	16	45
4	100	8	M16 x 2.0	16	45
5	125	16	M16 x 2.0	18	45
6	150	16	M16 x 2.0	18	50
8	200	16	M16 x 2.0	20	50
10	250	24	M16 x 2.0	22	55
12	300	24	M20 x 2.5	22	60

* Calculation Formula (PN6): Length = Flange Thk + 4mm (Gasket/Washer) + 1x Dia. Rounded to nearest 5mm.

EN 1092-1 PN10 Lug Valve Bolt Chart

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16 x 2.0	18	45
2.5	65	16	M16 x 2.0	18	45
3	80	16	M16 x 2.0	20	50
4	100	16	M16 x 2.0	20	50
5	125	16	M16 x 2.0	22	50
6	150	16	M20 x 2.5	22	60
8	200	16	M20 x 2.5	24	60
10	250	24	M20 x 2.5	26	65
12	300	24	M20 x 2.5	26	65
14	350	32	M20 x 2.5	26	65
16	400	32	M24 x 3.0	26	70
18	450	40	M24 x 3.0	28	75
20	500	40	M24 x 3.0	28	75
24	600	40	M27 x 3.0	28	80

* Note: PN10 and PN16 bolt patterns are identical for DN50-DN150 but differ for larger sizes.

EN 1092-1 PN16 Lug Valve Bolt Chart

Common Standard: PN16 is the most common standard for industrial water applications in Europe.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16 x 2.0	18	45
2.5	65	16	M16 x 2.0	18	45
3	80	16	M16 x 2.0	20	50
4	100	16	M16 x 2.0	20	50
5	125	16	M16 x 2.0	22	50
6	150	16	M20 x 2.5	22	60
8	200	24	M20 x 2.5	24	60
10	250	24	M24 x 3.0	26	70
12	300	24	M24 x 3.0	28	75
14	350	32	M24 x 3.0	30	75
16	400	32	M27 x 3.0	32	85
18	450	40	M27 x 3.0	34	90
20	500	40	M30 x 3.5	34	100
24	600	40	M33 x 3.5	36	110

* Calculation Basis: Length = EN 1092-1 Type 11 Flange Thickness + 2mm Gasket + 3mm Washer + 1x Bolt Diameter Engagement.

EN 1092-1 PN25 Lug Valve Bolt Chart

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16 x 2.0	20	45
2.5	65	16	M16 x 2.0	22	50
3	80	16	M16 x 2.0	24	50
4	100	16	M20 x 2.5	24	60
5	125	16	M24 x 3.0	26	70
6	150	16	M24 x 3.0	28	70
8	200	24	M24 x 3.0	30	75
10	250	24	M27 x 3.0	32	80
12	300	32	M27 x 3.0	34	85
14	350	32	M30 x 3.5	38	95
16	400	32	M33 x 3.5	40	105
18	450	40	M33 x 3.5	46	110
20	500	40	M33 x 3.5	48	115
24	600	40	M36 x 4.0	48	120

EN 1092-1 PN40 Lug Valve Bolt Chart

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16 x 2.0	20	45
2.5	65	16	M16 x 2.0	22	50
3	80	16	M16 x 2.0	24	50
4	100	16	M20 x 2.5	24	60
5	125	16	M24 x 3.0	26	70
6	150	16	M24 x 3.0	28	70
8	200	24	M27 x 3.0	34	85
10	250	24	M30 x 3.5	38	95
12	300	32	M30 x 3.5	42	100
14	350	32	M33 x 3.5	46	110
16	400	32	M36 x 4.0	50	120
18	450	40	M36 x 4.0	56	125
20	500	40	M39 x 4.0	56	135
24	600	40	M45 x 4.5	68	155

* Note: PN25 and PN40 are identical for sizes DN50 through DN150.

EN 1092-1 PN63 Lug Valve Bolt Chart

High Pressure: Verify Valve Body Geometry. Lengths below are estimates based on standard Weld Neck flange thickness.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M20 x 2.5	26	65
2.5	65	16	M20 x 2.5	26	65
3	80	16	M20 x 2.5	28	70
4	100	16	M24 x 3.0	30	75
5	125	16	M27 x 3.0	32	85
6	150	16	M30 x 3.5	34	90
8	200	24	M33 x 3.5	42	110
10	250	24	M33 x 3.5	46	110
12	300	32	M36 x 4.0	52	125

EN 1092-1 PN100 Lug Valve Bolt Chart

Critical Check: For PN100, do NOT rely solely on the calculated length. The thread depth in the valve body varies significantly by manufacturer.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Length (mm)
2	50	8	M20 x 2.5	28	Check Mfg
2.5	65	16	M24 x 3.0	30	Check Mfg
3	80	16	M24 x 3.0	32	Check Mfg
4	100	16	M27 x 3.0	36	Check Mfg
5	125	16	M30 x 3.5	40	Check Mfg
6	150	16	M33 x 3.5	44	Check Mfg
8	200	24	M36 x 4.0	52	Check Mfg
10	250	24	M39 x 4.0	60	Check Mfg
12	300	32	M45 x 4.5	68	Check Mfg

JIS 5K Lug Valve Bolt Chart

Low Pressure: JIS 5K flanges are relatively thin. Ensure bolts do not bottom out in the valve body.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (JIS Metric)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M12	10	25
2.5	65	8	M12	10	25
3	80	8	M16	12	35
4	100	16	M16	14	35
5	125	16	M16	16	40
6	150	16	M16	16	40
8	200	16	M20	20	50
10	250	24	M20	22	50
12	300	24	M20	22	50

* Calculation Basis (5K): Length = Flange Thk + 3mm (Gasket/Washer) + 1x Dia. Rounded to nearest 5mm.

JIS 10K Lug Valve Bolt Chart

Standard Industrial: The most common JIS standard. Quantity reflects total cap screws for both sides.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (JIS Metric)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16	16	40
2.5	65	8	M16	18	40
3	80	16	M16	18	40
4	100	16	M16	18	40
5	125	16	M20	20	50
6	150	16	M20	22	50
8	200	24	M20	22	50
10	250	24	M22	24	55
12	300	32	M22	24	55
14	350	32	M22	26	60
16	400	32	M24	28	60
18	450	40	M24	30	65
20	500	40	M24	30	65
24	600	48	M30	32	75

* Calculation Basis (10K): Length = Flange Thk + 4mm (Gasket/Washer) + 1x Dia. Rounded to nearest 5mm.

JIS 16K Lug Valve Bolt Chart

Warning: JIS 16K flanges are thicker than 10K. Bolt length must be calculated based on the specific valve body thread depth.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (JIS Metric)	Ref. Flange Thk (mm)	Length (mm)
2	50	16	M16	16	Check Mfg
2.5	65	16	M16	18	Check Mfg
3	80	16	M20	20	Check Mfg
4	100	16	M20	22	Check Mfg
5	125	16	M22	22	Check Mfg
6	150	24	M22	24	Check Mfg
8	200	24	M22	26	Check Mfg
10	250	24	M24	28	Check Mfg
12	300	32	M24	30	Check Mfg

Note: 16K hole patterns differ significantly from 10K in larger sizes.

JIS 20K Lug Valve Bolt Chart

High Pressure: Requires high-tensile bolts. Flange thickness is significant. Verify thread engagement depth with valve drawing.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (JIS Metric)	Ref. Flange Thk (mm)	Length (mm)
2	50	16	M16	16	Check Mfg
2.5	65	16	M16	18	Check Mfg
3	80	16	M20	20	Check Mfg
4	100	16	M20	22	Check Mfg
5	125	16	M22	24	Check Mfg
6	150	24	M22	26	Check Mfg
8	200	24	M22*	28	Check Mfg
10	250	24	M24*	30	Check Mfg
12	300	32	M24*	32	Check Mfg

* Important: Bolt diameters for JIS 20K sizes DN200 and larger may vary between M22, M24, and M30 depending on the specific year of the JIS standard and flange type (SOP vs WN). Always measure the flange holes.

AS 2129 Table D Lug Valve Bolt Chart

Application: Low Pressure / Waterworks. Common in irrigation.

Thread Note: Original standard specifies BSW. Modern installations almost exclusively use Metric (M) bolts in the clearance holes.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (Modern Metric)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16	13	35
2.5	65	8	M16	13	35
3	80	8	M16	13	35
4	100	8	M16	14	35
5	125	16	M16	14	35
6	150	16	M16	14	35
8	200	16	M16	16	40
10	250	16	M20	17	45
12	300	24	M20	19	50

* Formula: Length = Flange Thk + 3mm (Washer/Gasket) + 1x Dia. Rounded to nearest 5mm.

AS 2129 Table E Lug Valve Bolt Chart

Standard: The most common flange standard in Australia for general industry.

Warning: Note the 8-bolt pattern on DN100 (Table D uses 4 bolts).

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (Modern Metric)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16	14	35
2.5	65	8	M16	14	35
3	80	8	M16	14	35
4	100	16	M16	16	40
5	125	16	M16	17	40
6	150	16	M20	19	45
8	200	16	M20	19	45
10	250	24	M20	22	50
12	300	24	M24	25	60
14	350	24	M24	29	60
16	400	24	M24	32	65
18	450	32	M24	35	70
20	500	32	M24	38	70
24	600	32	M30	48	85

* Formula: Length = Flange Thk + 4mm (Washer/Gasket) + 1x Dia. Rounded to nearest 5mm.

AS 2129 Table F Lug Valve Bolt Chart

High Pressure: Table F flanges are significantly thicker. Verify valve thread depth before installation.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (Modern Metric)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M20	16	45
2.5	65	16	M20	17	45
3	80	16	M20	19	45
4	100	16	M20	22	50
5	125	16	M24	25	55
6	150	24	M24	29	60
8	200	24	M24	32	65
10	250	24	M30	35	75
12	300	32	M30	41	80
14	350	32	M33	48	Check Mfg
16	400	32	M33	54	Check Mfg

Note: Larger sizes (>DN300) have variable valve body geometry. Please measure.

GOST 33259 / 12815 PN6 Lug Valve Bolt Chart

Standard: GOST PN6 is similar to DIN PN6. Uses smaller metric bolts.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M12 x 1.75	12	30
2.5	65	8	M12 x 1.75	12	30
3	80	8	M16 x 2.0	14	35
4	100	8	M16 x 2.0	14	35
5	125	16	M16 x 2.0	16	40
6	150	16	M16 x 2.0	16	40
8	200	16	M16 x 2.0	18	40
10	250	24	M16 x 2.0	20	45
12	300	24	M20 x 2.5	22	50

* Formula: Length = Flange Thk + 4mm (Washer/Gasket) + 1x Dia. Rounded to nearest 5mm.

GOST 33259 / 12815 PN10 Lug Valve Bolt Chart

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16 x 2.0	14	35
2.5	65	8	M16 x 2.0	16	40
3	80	16	M16 x 2.0	16	40
4	100	16	M16 x 2.0	16	40
5	125	16	M16 x 2.0	18	40
6	150	16	M20 x 2.5	18	45
8	200	16	M20 x 2.5	20	45
10	250	24	M20 x 2.5	22	50
12	300	24	M20 x 2.5	22	50
14	350	32	M20 x 2.5	22	50
16	400	32	M24 x 3.0	22	55

GOST 33259 / 12815 PN16 Lug Valve Bolt Chart

Common: The most widely used general industrial standard in CIS regions.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16 x 2.0	14	35
2.5	65	8	M16 x 2.0	16	40
3	80	16	M16 x 2.0	16	40
4	100	16	M16 x 2.0	16	40
5	125	16	M16 x 2.0	18	40
6	150	16	M20 x 2.5	18	45
8	200	24	M20 x 2.5	20	45
10	250	24	M24 x 3.0	22	55
12	300	24	M24 x 3.0	24	55
14	350	32	M24 x 3.0	26	60
16	400	32	M27 x 3.0	28	65

* Note on DN80: Confirm if 4-bolt or 8-bolt pattern is required. GOST 33259 specifies 8 holes, but legacy valves may differ.

GOST 33259 / 12815 PN25 Lug Valve Bolt Chart

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16 x 2.0	16	35
2.5	65	16	M16 x 2.0	18	40
3	80	16	M16 x 2.0	20	40
4	100	16	M20 x 2.5	22	50
5	125	16	M24 x 3.0	24	55
6	150	16	M24 x 3.0	26	55
8	200	24	M24 x 3.0	28	60
10	250	24	M27 x 3.0	30	65
12	300	32	M27 x 3.0	32	65

GOST 33259 / 12815 PN40 Lug Valve Bolt Chart

Thick Flanges: PN40 flanges are robust. Ensure bolt length accounts for full thread engagement.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Calc. Length (mm)*
2	50	8	M16 x 2.0	16	35
2.5	65	16	M16 x 2.0	18	40
3	80	16	M16 x 2.0	20	40
4	100	16	M20 x 2.5	22	50
5	125	16	M24 x 3.0	24	55
6	150	16	M24 x 3.0	26	55
8	200	24	M27 x 3.0	30	65
10	250	24	M30 x 3.5	34	70
12	300	32	M30 x 3.5	38	75

GOST 33259 / 12815 PN63 Lug Valve Bolt Chart

Strictly Reference: For PN63, valve body thread depth is not standardized. Check valve drawing.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Length (mm)
2	50	8	M20 x 2.5	22	Check Mfg
2.5	65	16	M20 x 2.5	24	Check Mfg
3	80	16	M20 x 2.5	24	Check Mfg
4	100	16	M24 x 3.0	26	Check Mfg
5	125	16	M27 x 3.0	30	Check Mfg
6	150	16	M30 x 3.5	32	Check Mfg
8	200	24	M33 x 3.5	36	Check Mfg
10	250	24	M33 x 3.5	40	Check Mfg
12	300	32	M36 x 4.0	44	Check Mfg

GOST 33259 / 12815 PN100 Lug Valve Bolt Chart

Critical: High Pressure. Do not estimate lengths. Use only Manufacturer Certified Drawings.

Valve Size		Bolting Hardware (Metric Cap Screws)
NPS (Ref)	DN (mm)	Total Qty (Both Sides)	Thread Size (M x Pitch)	Ref. Flange Thk (mm)	Length (mm)
2	50	8	M24 x 3.0	24	Check Mfg
2.5	65	16	M24 x 3.0	26	Check Mfg
3	80	16	M24 x 3.0	28	Check Mfg
4	100	16	M27 x 3.0	32	Check Mfg
5	125	16	M30 x 3.5	36	Check Mfg
6	150	16	M33 x 3.5	40	Check Mfg
8	200	24	M36 x 4.0	46	Check Mfg
10	250	24	M39 x 4.0	52	Check Mfg
12	300	32	M45 x 4.5	60	Check Mfg

Other National Standards

Beyond the major global standards, many countries maintain national or industry-specific flange standards. Butterfly valve bolt patterns must align with these if specified.

The Universal Principle

Regardless of the standard, the core principle remains: The valve's drilling pattern must exactly match the flange's drilling pattern. This includes the bolt circle diameter (BCD), number of holes, and hole diameter.

Common Regional and Industrial Standards

GB/T (China): Guobiao standards are the national standards for China. Standards like GB/T 9113 (for integral steel pipe flanges) and others dictate flange dimensions. While some are harmonized with ISO, direct compatibility with ASME/EN is not guaranteed.
HG/T (China - Chemical Industry): These are Chinese standards specific to the chemical industry, such as HG/T 20592. They often define flange requirements for specific applications and pressures within this sector and must be adhered to for relevant projects.
KS (Korean Industrial Standards - South Korea): Defined by standards such as KS B 1503, these flanges use "K" pressure ratings (e.g., 10K, 20K) and share significant dimensional similarities with JIS standards. They are generally not interchangeable with ASME or EN flanges, requiring specific metric bolting configurations based on the pressure class.
SABS / SANS (South Africa): The South African Bureau of Standards issues standards like SANS 1123, which specifies dimensions for pipe flanges. These are often based on BS or ISO standards but require explicit confirmation.

The Rule for "Other" Standards

When encountering a non-ASME/EN/JIS/AS standard, it is mandatory to obtain the technical specification sheet for both the valve and the mating flange to perform a manual verification of:

Bolt Circle Diameter (BCD)
Number of Bolt Holes
Diameter of Bolt Holes

Never assume compatibility based on nominal pipe size alone.

Golden Rules of Bolt & Cap Screw Selection

Mistakes in bolting are costly and dangerous. Adhering to these rules prevents installation failure, leaks, and safety incidents.

1 Rule 1: Always Verify the Mating Flange Standard.

This is the most critical step. Before consulting any chart, you must know the exact standard, pressure class, and size of the flange your valve will be installed between. A "DN150" flange can be PN10, PN16, ASME Class 150, or JIS 10K—each with different bolting.

2 Rule 2: Differentiate Wafer vs. Lug.

Wafer valves use fewer, longer through-bolts that clamp the entire assembly. Lug valves use twice as many shorter cap screws, bolting each flange to the valve body independently. Using the wrong chart will result in incorrect bolt quantity and type.

3 Rule 3: Bolt Length is Critical and is NOT in These Charts.

These charts provide the quantity and diameter, not the length. For Wafer Valves: Length = (Flange 1 Thickness) + (Valve Body Thickness) + (Flange 2 Thickness) + (2 x Gasket Thickness) + (2 x Nut Height) + (Extra Thread Projection). For Lug Valves: Length depends on flange thickness and required thread engagement in the valve body (typically 1 to 1.5 times the bolt diameter). Always calculate length based on the specific assembly components.

4 Rule 4: Match Bolt Material to Service Conditions.

The bolt material must be compatible with the fluid temperature, pressure, and environment. Common choices include ASTM A193 B7 for standard carbon steel applications and A193 B8/B8M for stainless steel or corrosive services. Mismatched materials can lead to corrosion or mechanical failure.

5 Rule 5: The Manufacturer's Datasheet is the Final Authority.

While these charts are comprehensive references based on standards, slight variations can exist between manufacturers. The valve manufacturer's certified dimensional drawing and installation manual are the ultimate source of truth. Use these charts for planning, but ALWAYS confirm with the manufacturer's official documentation before final procurement or fabrication.

The Definitive Digital Lexicon of Global Flange Standards

The Master Chart for Butterfly Valve Cap Screws (Lug Style)

The Ultimate Butterfly Valve Bolt Size & Length Chart

Article Paths

Lug vs. Wafer: Understanding the Bolting Difference

Wafer Style (Through-Bolts)

Lug Style (Cap Screws)

LUG VS. WAFER BOLT COUNT

ASME Class 150 Wafer Valve Bolt Chart

ASME Class 300 Wafer Valve Bolt Chart

Wafer Style: ASME Class 600 (High Pressure)

Standard: ASME B16.5

ASME Class 900 Wafer Valve Bolt Chart

Wafer Style: EN 1092-1 PN 6

Engineering Note: PN 6

Wafer Style: EN 1092-1 PN 10

Standard Note

Wafer Style: EN 1092-1 PN 16

Standard Note

Wafer Style: EN 1092-1 PN 25

Standard: EN 1092-1

Wafer Style: EN 1092-1 PN 40

Standard Note

Wafer Style: EN 1092-1 PN 63 (PN 64)

Standard Note

* Important Note on Bolt Lengths

Wafer Style: EN 1092-1 PN 100

Standard: EN 1092-1 (High Pressure)

Wafer Style: DIN PN 6 (DIN 2631)

Standard Note: DIN 2501 / 2631

Wafer Style: DIN PN 10 (DIN 2632)

Standard Note

Wafer Style: DIN PN 16 (DIN 2633)

Standard Note

Wafer Style: DIN PN 25

Standard: DIN 2634

Wafer Style: DIN PN 40 (DIN 2635)

Standard Note

Wafer Style: DIN PN 64 (DIN 2636)

Standard Note

* Wrench Size Note

Wafer Style: DIN PN 100 (Very High Pressure)

Standard: DIN 2637

Wafer Style: BS 4504 PN 6 (Metric)

Standard Note: BS 4504

Wafer Style: BS 4504 PN 10 (Metric)

Standard Note

Wafer Style: BS 4504 PN 16 (Metric)

Standard Note

Wafer Style: BS 4504 PN 40 (Metric)

Standard Note

Wafer Style: BS 4504 PN 64 (Metric)

Standard Note

Wafer Style: JIS 5K Flanges

Standard Note: JIS B 2220 5K

Wafer Style: JIS 10K Flanges

Standard Note: JIS B 2220 10K

Wafer Style: JIS 16K Flanges

Standard Note: JIS B 2220 16K

Wafer Style: JIS 20K Flanges

Standard Note: JIS B 2220 20K

* Calculation Note for JIS Wafer Valves

Wafer Style: AS 2129 Table D

Standard Note: Table D

Wafer Style: AS 2129 Table E

Standard Note: Table E

Wafer Style: AS 2129 Table F

Standard Note: Table F

Wafer Style: AS 2129 Table H

Standard Note: Table H

Wafer Style: GOST PN 6

Standard: GOST 33259-2015

Wafer Style: GOST PN 10

Standard Note

Wafer Style: GOST PN 16

Standard Note

Wafer Style: GOST PN 25

Standard Note: PN 25

Wafer Style: GOST PN 40

Standard Note

Wafer Style: GOST PN 63

Standard Note: PN 63