Gasket & Bolting Quick Reference

Gasket types, m/y values, bolt stress allowables, and torque reference for flanged joint assembly.

Bolt Data

ASME B16.5 Flange Bolt Data · Class 150

NPS	# Bolts	Bolt Dia (in)	Bolt Circle (in)	Bolt Length (in)	Flange OD (in)	Raised Face OD (in)	Raised Face ID (in)	Gasket ID (in)	Gasket OD (in)
0.5	4	0.5	2.375	2.25	3.5	1.38	0.84	0.88	1.38
0.75	4	0.5	2.75	2.5	3.88	1.69	1.05	1.09	1.69
1	4	0.5	3.125	2.5	4.25	2	1.32	1.36	2
1.5	4	0.5	3.875	2.75	5	2.88	1.9	1.94	2.88
2	4	0.625	4.75	3.25	6	3.62	2.38	2.44	3.62
3	4	0.625	6	3.5	7.5	5	3.5	3.57	5
4	8	0.625	7.5	3.75	9	6.19	4.5	4.57	6.19
6	8	0.75	9.5	4	11	8.5	6.63	6.72	8.5
8	8	0.75	11.75	4.5	13.5	10.62	8.63	8.72	10.62
10	12	0.875	14.25	5	16	12.75	10.75	10.88	12.75
12	12	0.875	17	5.25	19	15	12.75	12.88	15
14	12	1	18.75	5.75	21	16.25	14	14.14	16.25
16	16	1	21.25	6	23.5	18.5	16	16.16	18.5
18	16	1.125	22.75	6.5	25	21	18	18.18	21
20	20	1.125	25	6.75	27.5	23	20	20.2	23
24	20	1.25	29.5	7.25	32	27.25	24	24.25	27.25
Class 300
NPS	# Bolts	Bolt Dia (in)	Bolt Circle (in)	Bolt Length (in)	Flange OD (in)
0.5	4	0.5	2.625	2.75	3.75
0.75	4	0.625	3.25	3.25	4.62
1	4	0.625	3.5	3.25	4.88
1.5	4	0.75	3.875	3.75	5.25
2	8	0.625	5	3.75	6.5
3	8	0.75	6.125	4.25	8.25
4	8	0.75	7.875	4.5	10.75
6	12	0.75	10.625	4.75	12.5
8	12	0.875	13	5.5	15
10	16	1	15.25	6	17.5
12	16	1.125	17.75	6.5	20.5
14	20	1.125	20.25	7	23
16	20	1.25	22.5	7.25	25.5
18	24	1.25	24.75	7.75	28
20	24	1.25	27	8	30.5
24	24	1.5	32	9	36

Gasket Types

Gasket Selection Guide

Gasket Type	ASME Code	Max Temp (°F)	Max Pressure (psig)	m Factor	y Factor (psi)	Typical Applications
Spiral Wound (graphite fill)	B16.20	850	2500	3	10000	Standard refinery service, most common gasket type
Spiral Wound (PTFE fill)	B16.20	500	1500	2.5	10000	Chemical service, clean fluids, corrosive media
Spiral Wound (ceramic fill)	B16.20	1800	2500	3	10000	Very high temperature service
Ring Joint (RTJ)	B16.20	1500	10000	5.5	18000	High pressure, critical service, Class 600+
Compressed Fiber (non-asbestos)	—	750	1200	2	3700	Low pressure utility service, water, air, steam
Flexible Graphite Sheet	—	850	2500	3	4500	High temp, good sealability, moderate pressure
PTFE Envelope	—	400	300	2	2000	Highly corrosive service, HF, strong acids
Kammprofile (grooved metal)	—	1000	2500	3.5	12000	Difficult sealing, irregular flanges, high reliability
Corrugated Metal (w/ graphite)	—	900	1500	3	8000	Heat exchangers, moderate duty
Double-Jacketed	—	1000	3000	3.75	12500	High pressure, heat exchangers
Metal O-Ring	—	1500	10000	5	15000	Extreme conditions, critical sealing

Torque Tables

Bolt Torque Values (ft-lbs) · Per ASME PCC-1 guidelines. Values assume uniform bolt loading. K-factor method.

Bolt Size (in)	Stress Area (in²)	Target Stress (ksi)	Torque (dry) K=0.20 (ft-lb)	Torque (moly) K=0.15 (ft-lb)	Torque (anti-seize) K=0.12 (ft-lb)
1/2	0.1419	40	47	35	28
5/8	0.226	40	94	71	57
3/4	0.334	40	167	125	100
7/8	0.4617	40	269	202	162
1	0.6057	40	404	303	242
1-1/8	0.7627	40	572	429	343
1-1/4	0.9691	40	808	606	485
1-3/8	1.1549	40	1059	794	635
1-1/2	1.4053	40	1405	1054	843
1-5/8	1.6805	40	1821	1365	1092
1-3/4	1.9799	40	2310	1732	1386
2	2.6507	40	3534	2651	2121
2-1/4	3.4234	40	5135	3851	3081
2-1/2	4.2919	40	7153	5365	4292
2-3/4	5.2588	40	9641	7231	5785
3	6.324	40	12648	9486	7589

Bolt Calculator

Bolt Load & Torque Calculator · INPUT DATA

Bolt Nominal Diameter		inches
Bolt Tensile Stress Area		in² (from bolt table)
Number of Bolts
Target Bolt Stress	40	ksi (typical: 40 ksi for B7, 25 for B8)
Nut Factor (K)	0.15	(0.20 dry, 0.15 moly, 0.12 anti-seize)
CALCULATED RESULTS
Bolt Load (per bolt)	0	lbs
Total Bolt Load	0	lbs
Target Torque (per bolt)	0	ft-lbs
Gasket Load (approx)	0	lbs (= total bolt load at seating)
BOLT-UP PASS SEQUENCE (PCC-1)
Pass 1 — Star Pattern	0	ft-lbs
Pass 2 — Star Pattern	0	ft-lbs
Pass 3 — Star Pattern	0	ft-lbs
Pass 4 — Circular (clockwise)	0	ft-lbs

Source: Gasket_Bolting_Quick_Reference_v1.xlsx

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