Page 42 - Design Criteria.qxd

43 ® Welcome to the Next Generation of Sealing Technology
Type Material Gb (psi) a Gs (psi)
Spiral Wound ‘LS’ SS/Flexicarb 598 0.385 0.03
(Class 150 & 300) SS/PTFE 698 0.249 0.00128
Spiral Wound SS/Flexicarb 2300 0.237 13
(Class 150 to 2500) SS/Flexite Super 2600 0.230 15
SS/Thermiculite 835 2,120 0.190 49
MRG SS/Flexicarb 813 0.338 0.2
Carrier Ring SS/Flexicarb 1251 0.309 11
Flexpro SS/Flexicarb 387 0.334 14
SS/Thermiculite 845 1780 0.169 1080
Sheet Gaskets Flexicarb 1047 0.354 0.07
(Class 150 to 300) Flexicarb NR 818 0.347 0.07
AF 2100 1767 0.22 65.19
SF 2400/2800 290 0.383 2.29
SF 3300 2360 0.190 50.25
Sigma 500 4 0.804 0.115
Sigma 511 209 0.356 0.00498
Sigma 522 472 0.250 0.037
Sigma 533 115 0.382 0.000065
Thermiculite 815 1906 0.2 456.12
Corrugated Gasket Soft Iron 3000 0.160 115
Stainless Steel 4700 0.150 130
Soft Copper 1500 0.240 430
Metal Jacketed Soft Iron 2900 0.230 15
Stainless Steel 2900 0.230 15
Soft Copper 1800 0.350 15
Metal Jacketed Corr. Soft Iron 8500 0.134 230
Please contact Flexitallic Engineering Department for the gasket constants of newly developed gaskets.
PVRC Method
11. Gasket Seating Stress, Sm2 = Gb (Tpa a ) / (e x 1.5) - Pd (A i /Ag)
e = 0.75 for manual bolt up
e = 1.0 for hydraulic tensioners & ultrasonic
12. Design factor, Mo = the greater of 2, Sm1/ P d or Sm2 / P d
13. Design Bolt load, Wmo = Ag x Smo + Ai x P d
Smo is the larger of Sm1, Sm2, 2P, S L
S L = A minimum permitted value of operating gasket stress equal to 90% of the minimum gasket stress in the test that determined the
gasket constants. It is 6.21 MPa (900 psi) for the standard and soft ROTT test procedures, and 10.3 MPa (1500 psi) for the hard gas-
ket procedure.
Gasket Factors
Note: All data presented in this table are based on currently available published information. PVRC and ASME continue to refine data
reduction techniques, and values are therefore subject to further review and revisions.