90系列低压先导式泄压阀
在1968年推出，这种先导式泄压阀带有弹性体的议席，天然气管道和化工密封箱应用而设计。低压系统可以受到保护，弹簧阀，重量装阀或先导阀压。
Introduced in 1968, this pilot operated pressure relief valve is designed with elastomer seats and seals for gas piping and chemical tank applications.
Function – Low Pressure POPRV
Low pressure systems can be protected from overpressure by spring-operated valves, weight-loaded valves or pilot operated valves.
Full Open at Set Pressure
Weight-loaded and spring-operated valves begin to open when forces are in equilibrium. As process pressures approach set pressures, there can be significant simmer or leakage and loss of product. Long periods of simmer can lead to valve freeze-up with cryogenic fluids. Very small differential forces don’t easily overcome sticky fluids and prevent proper opening. Typical weight-loaded valves require significant overpressure to achieve rated capacities.
Features & Benefits:
- Tight Up to Set Pressure: Pilot control keeps high seat forces all the way to set point, helping eliminate product losses.
- Full Open at Set Point: Snap action opening permits full opening at set pressure, allowing for higher settings and overcoming freezing or sticking problems.
- Pop or Modulating Action: Pilot selection allows a choice between rapid snap opening action and proportional modulating action to best suit the process.
- Resilient Seats and Diaphragms: Extensive selection of seat and diaphragm materials to meet most conditions and provide long maintenance-free operation.
- Balanced Against Back Pressure: Valves can be connected to closed header systems without loss of valve lift or set pressure fluctuations.
- Remote Sensing: This option permits the pressure in the protected system to be accurately sensed at the PRV regardless of the inlet piping pressure losses to the PRV.
- Field Test Connection: Valve function can be verified in place without removing the valve to a test bench or raising process pressures.
- Manual Blowdown: The valve can be actuated manually or remotely to depressurize a system.
Specifications
Sizes: 2" x 3" to 12" x 16"
Orifices: 2.29 to 84.0 in2 [14.77 to 541.93 cm2]
Temperature Range: -260 to +300°F [-162 to +149°C]
Set Pressures: 3" wc to 50 psig [7.5 mbarg to 3.45 barg]
Code: ASME VIII [15 psig and above]
Type 93
The Type 93 is the original workhorse of the product range, providing excellent service since 1968. This pilot operated pressure relief valve is designed with elastomer seats and seals, with construction materials in aluminum, carbon steel (CS) and stainless steel (SS) to satisfy the majority of gas piping and chemical tank applications.
Types 91 and 94
The Types 91 and 94 were designed for specific applications where FEP diaphragms alone were not rugged enough and premium sealing was required for super cryogenic fluids. The Types 91 and 94 employ a bellows coupled with a Teflon® film seat to provide extraordinary performance for hard-to-hold cryogenic fluids such as hydrogen and helium. They also satisfy specific marine applications.
Type 95
The Type 95 is a unique higher pressure protection valve that utilizes a piston in the main valve for ruggedness, and high performance elastomers, making this valve ideal for special applications up to 150 psig [10.34 barg] in marine LPG services.
Type 96A
All of the above valves are pilot operated pressure relief valves. The Type 96A is a weight-loaded vacuum breaker designed to compliment the pressure relief products.
NOTE: The application of the 90 and 9000 Series flowing style pilot operated pressure relief valves in condensable gas service (ie: n-Butane, Isobutane or Butadiene) with operating fluid saturation temperatures that fall within the expected ambient temperature extremes require special consideration to assure the valve temperature remains above the operating fluid saturation temperature. Please contact your sales representative to review all applications, which fall within this categorization.
