Accessories & Parts

1330PSC Pressure Sensitive Close Feature


  • Pressure sensitive closing
  • Opens when pressure increases to set point
  • Allows the closing of the valve to be decreased until pressure returns to normal
  • Normally closed
  • Senses pressure increase either at valve inlet or outlet, depending on the application
  • Simple adjustment
  • Parts are replaceable while mounted on the valve
  • Rubber to metal seat for positive shutoff
  • Multiple spring ranges for accurate control

Under some pressure and flow conditions, closing a control valve may result in an undesirable increase in inlet or outlet pressure depending on the application. To prevent this, a valve may be equipped with a pressure sensitive closing feature which slows or stops the closing of the valve at a specific pressure setting until pressure returns to the set point. The pressure increase can be at the inlet or outlet of the valve, depending on the application. For example, on a pressure sustaining, altitude control or solenoid control valve, the pressure increase would be at the valve inlet; therefore the 1330PSC would sense inlet pressure. Conversely, on a check valve, the pressure increase would be at the valve outlet so the 1330PSC would sense outlet pressure.

The 1330PSC is a normally closed, two port pilot mounted on the main valve cover (bonnet). It senses valve pressure increase under its diaphragm and balances that pressure against an adjustable spring load. When sensed pressure increases to the set point, the pilot opens and vents the diaphragm chamber to slow or stop the closing of the valve. Venting is stopped when pressure is below the set point.

The 1330PSC Feature includes: tubing to connect to the main valve bonnet, sense line tubing to connect the sense pressure area of the main valve to the pilot diaphragm chamber, an isolation ball valve on the sense line and the OCV 1330 Pilot.

1330PSC Feature Application



Highlighted in blue, the 1330PSC is
shown sensing inlet pressure on a Model
108-4 Pressure Relief/Solenoid Valve.

1330PSC Components

  1. 1330 Pilot
  2. Vent
  3. Sense Line
  4. 141-4 Ball Valve




Highlighted in blue, the 1330PSC is1330onesheet.qxd
shown sensing outlet pressure on a
Model 94-3 Check Valve.

1330PSC Components

  1. 1330 Pilot
  2. Sense Line
  3. 141-1 Check Valve
  4. 141-4 Vent Ball Valve


Spring Range Options

5-30 35-210
20-80 140-560
65-180 450-1240
100-300 700-2100



Stainless Steel ASTM A743/CF8-M
Elastomers (diaphragm, seat disc, o-rings)

  • Buna-N (Std.)
  • Viton® (Opt.) Viton is a registered trademark of DuPont Dow Elastomers
  • EPDM (Opt.)


Rubber components are typically the only parts that may require periodic replacement. These are available in kits consisting of the diaphragm, the seat disc and all O-rings.

Buna-N Kit – Part # 930000
Viton® Kit – Part # 930100
EPDM Kit – Part # 930400