MODELS 264/265/266/267 SAFETY AND RELIEF VALVES
• Extra heavy rugged construction.
• Top guided design offers high capacity with 0.110 in2 (0.710 cm2) orifice area.
• Seats lapped to optical flatness.
• Ball pivot between disc and spring corrects misalignment and compensates for spring side thrust.
• Standard outlet with 1″ female NPT.
• O-ring soft seat available.
• Each valve tested and inspected for pressure setting and leakage.
• Maximum back pressure 400 psig (27.6 barg)4.
NOTES
1. ASME standard valves for air or steam service must have a lift lever.
2. Due to the capacity of these valves, thrust calculations should be reviewed and valve supported accordingly.
3. Pressures are for female NPT inlets only.
4. Back pressure increases set pressure on a one to one basis, and reduces capacity. Back pressure in excess of 10% of set pressure is not recommended.
GENERAL APPLICATION
These valves are suitable for the protection of pumps, compressors, pressure vessels or systems handling corrosive fluids or vapors at high pressure and/or temperature. Also for sentinel (warning) services on steam equipment.
TECHNICAL DATA
| Connections: | Threaded NPT or BSPT |
| Sizes: | 2”, 2½”, 3” |
| Temperature range: | |
| Model 264: | -20° to 550°F (-29° to 288°C) |
| Model 266: | -320° to 550°F (-195° to 288°C) |
| Model 265: | -20° to 750°F (-29° to 399°C) |
| Model 267: | -320° to 750°F (-195° to 399°C) |
| Pressure ranges[3] | |
| Air, gas and liquid: | 4 to 3300 psig (0.28 to 227 barg) |
| Steam: | To 2000 psig (137.9 barg) |
| Code: | asMe viii |
PARTS AND MATERIALS
| No. | Part Name | 264, 265 | 266, 267 |
| 1 | Nozzle[1] | SS SA351-CF8M | SS SA351-CF8M |
| 2 | Lock screw | SS commercial 18-8 | SS commercial 18-8 |
| 3 | Gasket | PTFE | PTFE |
| 4 | Spring pin | SS commercial | SS commercial |
| 5 | Guide | SS A743-CF8M | SS A743-CF8M |
| 7 | Disc | SS A479-316 | SS A479-316 |
| 9 | Stem retainer | SS A479-316 | SS A479-316 |
| 10 | Stem | SS A479-316 | SS A479-316 |
| 11 | Spring[2] | A313-316 or 6312[2] | A313-316 or 6312[2] |
| 12 | Spring step | SS A479-316 | SS A479-316 |
| 13 | Bonnet | Steel SA216-WCB | SS A743-CF8M |
| 14 | Jam nut | SS A479-316 | SS A479-316 |
| 15 | Compression screw | SS A479-316 | SS A479-316 |
| 16 | Cap | Steel A108 | SS A479-316 |
| 17 | Cap gasket | PTFE | PTFE |
| 18 | Soft seat disc | SS A479-316 | SS A479-316 |
| 19 | Disc insert | SS A479-316 | SS A479-316 |
| 20 | O-ring[3] |
NOTES
1. SA479-316 for female inlet.
2. tungsten alloy steel (X750 B637 or asM5699) for models 265, 267
3. Material letter designation
Buna-N (NBR) – B
Ethylene propylene (EPR/EPDM) – E
Neoprene – N
Silicone – S
Viton®* (FKM) – V
MODELS 264, 265, 266 AND 267 Metal seat
SPECIFICATIONS
| Size | Dimensions in inch (mm) | ||||
| Inlet | Outlet | A | B | C | Weight lb (kg) |
| ½”, ¾”, 1” | ¾”, 1” | 3 1/16 (77.8) | 1¾ (44.5) | 7½ (190.5) | 4 ½ (2.3) |
Dimensions are for reference only
ALL MODELS SOFT SEAT
MODELS OVERVIEW
Model 264: Carbon steel (CS) housing with 316 stainless steel (SS) trim (nozzle and disc), SS spring. Pressure-tight cap. For temperatures -20° to 550°F (-29° to 288°C).
Model 264P: With pressure-tight packed lift lever.
Model 265: As model 264 except high-temperature alloy spring. For temperatures -20° to 750°F (-29° to 399°C).
Model 265P: With pressure-tight packed lift lever.
Model 266: As model 264 except all 316 SS materials. For temperatures -320° to 550°F (-195° to 288°C)
Model 266P: With pressure-tight packed lift lever.
Model 267: As model 266 except high-temperature alloy spring. For temperatures -320° to 750°F (-195° to 399°C).
Model 267P: With pressure-tight packed lift lever.
NOTE
* Viton is a registered trademark of DuPont Performance elastomers L.L.C.
MODELS 264, 265, 266 AND 267
MODELS 264P, 265P, 266p AND 267P – PACKED LEVER
| No. | Part Name | 264P/265P | 266P/267P |
| 1 | Nozzle[1] | SS SA479-316 | SS SA479-316 |
| 2 | Lock screw | SS commercial | SS commercial |
| 3 | Bonnet | Steel SA216-WCB | SS A351-CF8M |
| 4 | Spring pin | SS commercial | SS commercial |
| 5 | Guide | SS A351-CF8M | SS A351-CF8M |
| 7 | Disc | SS SA479-316 | SS SA479-316 |
| 8 | Stem retainer | SS SA479-316 | SS SA479-316 |
| 9 | Retainer nut | SS SA479-316 | SS SA479-316 |
| 10 | Spring step | SS SA479-316 | SS SA479-316 |
| 11 | Stem | SS SA479-316 | SS SA479-316 |
| 12 | Spring[2] | SS A313-316, optional 6312 | SS A313-316, optional 6312 |
| 13 | Compression screw | SS SA479-316 | SS SA479-316 |
| 14 | Gasket - body | PTFE | PTFE |
| 15 | Cap | SS A743-CF8M | SS A743-CF8M |
| 16 | Jam nut | SS SA479-316 | SS SA479-316 |
| 17 | Lift cam | SS A743-CF8M | SS A743-CF8M |
| 18 | Cotter pin | Steel commercial | Steel commercial |
| 19 | Lever | Steel A108 zinc plated | Steel A108 zinc plated |
| 20 | Drive screw | SS commercial | SS commercial |
| 21 | O-ring | NBR | NBR |
| 22 | Lift nut | SS SA479-316 | SS SA479-316 |
| 23 | Lift washer | SS A756-440C | SS A756-440C |
| 24 | Cap gasket | PTFE | PTFE |
NOTES
1. SA351-CF8M for male inlet.
2. Tungsten alloy steel for models 265, 267.
Models 264P, 265P, 266P and 267P
SPECIFICATIONS
| Size | Dimensions in inch (mm) | ||||
| Inlet | Outlet | A | B | C | Weight lb (kg) |
| ½”, ¾”, 1” | ¾”, 1” | 3 1/16 (77.8) | 1¾ (44.5) | 9 (228.6) | 4 ½ (2.3) |
Dimensions are for reference only
Models 264P, 265P, 266P and 267P
CAPACITIES
ASME SECTION VIII, AIR/GAS AND STEAM, NON-CODE LIQUID
| Set pressure | Water non-code | Air | Steam |
| psig (barg) | GPM (m3/h) | SCFM (Nm3/h) | lb/h (kg/h) |
| 4 (0.3) | 5 (1) | 25 (44) | 79 (37) |
| 6 (0.4) | 5 (1) | 31 (50) | 96 (42) |
| 8 (0.6) | 6 (1) | 36 (61) | 109 (51) |
| 10 (0.7) | 6 (1) | 40 (66) | 120 (55) |
| 20 (1.4) | 8 (2) | 58 (97) | 164 (75) |
| 30 (2.1) | 10 (2) | 74 (123) | 207 (95) |
| 40 (2.8) | 11 (3) | 91 (152) | 255 (117) |
| 50 (3.5) | 13 (3) | 108 (180) | 302 (139) |
| 75 (5.2) | 15 (4) | 150 (249) | 422 (192) |
| 100 (6.9) | 18 (4) | 193 (319) | 541 (246) |
| 125 (8.6) | 20 (5) | 235 (388) | 660 (299) |
| 150 (10.3) | 22 (5) | 278 (457) | 780 (353) |
| 200 (13.8) | 25 (6) | 363 (600) | 1018 (463) |
| 250 (17.2) | 28 (6) | 447 (738) | 1257 (570) |
| 300 (20.7) | 31 (7) | 532 (881) | 1496 (680) |
| 350 (24.1) | 33 (8) | 617 (1020) | 1734 (787) |
| 400 (27.6) | 36 (8) | 702 (1162) | 1973 (897) |
| 500 (34.5) | 40 (9) | 872 (1444) | 2450 (1113) |
| 600 (41.4) | 44 (10) | 1042 (1725) | 2928 (1330) |
| 700 (48.3) | 47 (11) | 1212 (2006) | 3405 (1547) |
| 800 (55.2) | 51 (11) | 1382 (2287) | 3882 (1764) |
| 900 (62.1) | 54 (12) | 1552 (2569) | 4360 (1981) |
| 1000 (69.0) | 57 (13) | 1722 (2850) | 4837 (2198) |
| 1200 (83.0) | 62 (14) | 2062 (3421) | 5792 (2638) |
| 1400 (96.5) | 67 (15) | 2401 (3971) | 6746 (3063) |
| 1600 (111) | 72 (16) | 2741 (4562) | 7789 (3561) |
| 1800 (124) | 76 (17) | 3081 (5092) | 8885 (4031) |
| 2000 (138) | 80 (18) | 3421 (5662) | 10036 (4541) |
| 2250 (155) | 85 (19) | 3846 (6355) | - |
| 2500 (173) | 89 (20) | 4270 (7089) | - |
| 2750 (190) | 94 (21) | 4695 (7782) | - |
| 3000 (207) | 98 (22) | 5120 (8475) | - |
| 3300 (227) | 103 (23) | 5630 (9290) | - |
NOTES
1. 10% or 3 psig (0.2 barg) accumulation, whichever is greater.
2. Below 15 psig is non-code.
3. Orifice area = 0.110 square inch
MAXIMUM PRESSURE AND TEMPERATURE LIMITS – Male inlet connections
| Temperature | Air, steam, | water - psig (barg) | Air - psig (barg) | Steam, water - psig (barg) |
| °F (°c) | ½” (15) | ¾” (18) | 1” (25) | 1” (25) |
| 100 (38) | 1950 (134.4) | 3299 (227.5) | 3300 (227.5) | 3300 (227.5) |
| 200 (93) | 1675 (115.5) | 2836 (195.5) | 3300 (227.5) | 2933 (202.2) |
| 300 (149) | 1508 (104) | 2554 (176.1) | 3300 (227.5) | 2643 (182.2) |
| 350 (177) | 1435 (98.9) | 2432 (167.7) | 3300 (227.5) | 2539 (175.1) |
| 400 (204) | 1334 (92) | 2269 (156.4) | 3300 (227.5) | 2421 (166.9) |
| 450 (232) | 1257 (86.7) | 2146 (148) | 3300 (227.5) | 2335 (161) |
| 500 (260) | 1186 (81.8) | 2030 (140) | 3300 (227.5) | 2268 (156.4) |
| 550 (288) | 1127 (77.7) | 1935 (133.4) | 3300 (227.5) | 2186 (150.7) |
| 600 (316) | 1108 (76.4) | 1844 (127) | 3300 (227.5) | 2148 (148.1) |
| 650 (343) | 1095 (75.5) | 1805 (124.5) | 3300 (227.5) | 2090 (144.1) |
| 700 (371) | 1084 (74.7) | 1779 (122.7) | 3211 (221.4) | 2063 (142.2) |
| 750 (399) | 1055 (72.7) | 1770 (122) | 3157 (217.7) | 2029 (139.9) |
NOTE
1. Female inlet is rated to 3300 psi at 550°f for 264/266 and 750°f for 265/267.
SERVICE RECOMMENDATIONS FOR RESILIENT SEAT/SEAL MATERIALS
| Seat/seal materials | Service recommendation |
| Buna-N (NBR) (-30° to 250°F) (-34° to 121°C) | Air, anhydrous ammonia, butane, carbon dioxide, diesel oil, ethyl chloride, ethyl ether, freons #11 and 12, fuel oil, gasoline, helium, hydrogen sulphide, kerosene, lube oil, natural gas, nitrogen, oxygen (gas), propane, propylene, sulphur dioxide, vinyl chloride |
| Viton®* (FKM) (-10° to 406°F) (-23° to 208°C) | acetone, air, amyl alcohol, aniline, benzine, butane, carbon disulphide, carbon tetrachloride dowtherm ’a’ and ’J,’ ethyl chloride, ethylene, ethylene glycol, ethyl alcohol, gasoline, hexane, hydrogen sulphide, isobutyl alcohol, JP - 4 fuel, JP - 5 fuel, kerosene, lube oil, natural gas, naphtha, nitrogen, propane, propylene, propyl alcohol, sulphur dioxide, toluene, trichloroethylene, turpentine, water, xylene |
| Silicone (-100° to 406°F) (-73° to 208°C) | Air, helium, nitrogen, oxygen (gas) |
| Ethylene propylene (-70° to 400°F) (-57° to 205°C) | Steam, hot water |
| Neoprene (-45° to 300°F) (-43° to 149°C) | Air, anhydrous ammonia, butane, butyl alcohol, castor oil, denatured alcohol, ethanol, ethyl alcohol, freons (12, 13, 14 and 22), glycols, natural gas and silicate esters |
NOTE
* Viton is a registered trademark of DuPont Performance elastomers L.L.C.
SELECTION GUIDE
| Example: | 0264 | - | D | 01 | - | k | G | 1000 |
| Model 0264 264P 0265 265P 0266 266P 0267 267P | ||||||||
| Seat material M Metal B Buna-N (NBR)[1,2] E EPR[1,2] S Silicone[1,2] V Viton® (FKM)[1,2,6] N Neoprene[1],[2] | ||||||||
| Inlet size C ½" (12.7 mm) D ¾" (19.0 mm) E 1" (25.4 mm) | ||||||||
| Variation 01 MNPT x 1" FNPT 02 MNPT x ¾" FNPT 03 FNPT x 1" FNPT 04 FNPT x ¾" FNPT 60 MBSPT x 1" FBSPT | ||||||||
| Design revision Indicates non-interchangeable revision Dash (-) if original design | ||||||||
| Valve service K Air/gas asMe section viii models 264P, 265P, 266P, 267P required for air code service L steam ASME section viii models 264P, 265P, 266P, 267P required for steam code service M Non-code liquid, all models N Non-code air/gas, all models P Non-code steam, all models | ||||||||
| Spring material F[3] Air/gas asMe section viii models 264P, 265P, 266P, 267P required for air code service G[4] steam ASME section viii models 264P, 265P, 266P, 267P required for steam code service M[5] Non-code liquid, all models | ||||||||
| Set pressure 4 psig (0.3 barg) (0004) to 3300 psig (227 barg) (3300) |
NOTEs
1. Soft seat not available below 150 psi.
2. Not available for section VIII steam service.
3. Required for steam service ≥1030 psig.
4. For air service ≤ 2700 psig.
For steam service ≤ 1029 psig.
For liquid service ≤ 2699 psig.
5. For air service ≥ 2701 psig.
For liquid service ≥ 2700 psig.
6. Viton is a registered trademark of DuPont Performance elastomers L.L.C.
