Product Catalogue

High Performance - 2" thru 14"


Available in sizes 2" Thru 24"

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Seating and Un-seating Torque


Seating and un-seating torques are a function of the size of the valve and the shutoff pressure of the system.

Specific torque ratings can be found in the Seating/ Un-seating chart at the intersection of the 'size' row and the 'shutoff pressure' column. Torques listed are for PTFE and RTFE seated valves. For different seat materials specific multipliers are to be used as stated.

All torques listed are for normal service conditions (i.e. operating frequency is a minimum of once per month; disc corrosion is expected to be mild or minor, the media is a clean gas, liquid or steam, and is non-abrasive) and chemical affects upon the seat are minor.

Note

  1. Torques are applicable only to PTFE and RTFE seats. For fire-safe and metal seats, select only the torque applicable for the valve at 285 psig and multiply by 2.0.
  2. For other seat materials, select the torque applicable for the maximum differential pressure and multiply by the following factor:
    UHMWPE (Clean Service) x 1.3
    UHMWPE (Slurry Service) x 1.7

PTFE and RTFE Bi-directional Seating & Un-seating Torque Values


  Seating and Un-seating Torque (lbs. in.)
System Shutoff Pressure (PSIG)
Valve Size (in.) 150 psi 200 psi 285 psi 400 psi 500 psi 740 psi
2" 220 280 380 460 520 580
2 1/2 " 220 280 380 460 520 580
3" 250 320 430 520 590 650
4" 475 600 820 995 1,120 1,235
5" 925 1,125 1,350 1,570 1,750 1,900
6" 1,370 1,600 1,850 2,150 2,390 2,900
8" 2,060 2,330 3,200 4,020 4,870 6,720
10" 3,340 3,650 4,700 6,250 7,450 9,850
12" 4,590 5,250 6,400 8,160 9,590 12,940
14" 6,750 7,560 9,150 11,450 13,300 17,200
16" 9,350 10,450 12,500 15,000 17,500 22,200
18" 11,900 13,300 15,800 19,500 21,900 28,500
20" 15,600 17,500 21,000 25,200 28,700 36,140
24" 21,700 25,340 30,600 36,900 42,100 54,000
30" 29,200 35,000 43,500 54,500 62,500 80,000
36" 52,500 58,500 70,000 85,000 97,500 125,000

ANSI/FCI 70-2 Control Valve Seat Leakage, Tolerances and Test Specifications


ANSI B16.104-1976 Maximum Leakage Test Medium Pressure and Temperature
Class IV 0.01% valve capacity at full travel Air or water Service Δ P or 50 psig differential (3.4 bar differential), whichever is lower, at 50° to 125°F (10° to 52°C)
Class V  5 x 10-4 ml/min/psig/in. port dia.
(5 x 10-12 m3/sec/bar differential/mm port dia.) 		Water   Service Δ P at 50° to 125°F (10° to 52°C)
Class VI
Nominal Port Diameter (in.) Bubbles per Minute ml. per Minute
2 3 0.45
2 1/2 4 0.60
3 6 0.90
4 11 1.70
6 27 4.00
8 45 6.75
 Air or nitrogen  Service Δ P or 50 psig differential (3.4 bar differential), whichever is lower, at 50° to 125°F (10° to 52°C)

1. Polymer and Fire Safe Seats provide ANSI class VI shutoff.
2. Metal Seats provide ANSI Class IV shutoff.
3. All Polymer and Fire Safe Valves are factory tested for zero water leakage.
4. Reference ANSI/FCI 70-2 for further information.

 

Process Development & Control, Inc. reserves the right to make design improvements and/or change dimensions without notice.

Additional Information

1075 Montour West Industrial Park
Coraopolis, PA 15108
ph: 724.695.3440 toll free (US): 888-PDC-4070 fax: 724.695.8635
email: Sales@pdcvalve.com