FISHER 289H-41 relief Valves or Backpressure Regulators

The FISHER 289H-41 is a pressure relief valve or back pressure regulator, which is described below:

Connection size: 1 inch NPT threaded connection, this connection is widely used, easy to install and remove, and can be connected to a variety of piping systems.

Pressure parameters

Spring range: 1 - 4.5PSI.

Maximum Allowable Relief (Inlet) Pressure: 100 psig/6.9 bar, except for model 289H which has a maximum relief (inlet) pressure of 25 psig/1.7 bar.

Pressure Relief Setting Pressure Range: 5wc to 50psig (25mbar to 3.5bar), adjustable by spring setting to suit actual system pressure protection needs.

Temperature range: -20 to 150°F (-29 to 66°C) with Nitrile (NBR) and Chloroprene (CR) seals; 20 to 300°F (-7 to 149°C) with Fluorocarbon (FKM) (Models 289H and 289HH only).

Weight: 4 lb/2 kg for 1NPT.

Other Features: A spring-loaded, throttled pressure relief valve with a large diaphragm area and high sensitivity, ideal for low-pressure settings. Its smooth throttling operation minimizes pressure shock in the system during relief operation. With a pilot tube booster, this model achieves the highest possible relief capacity with minimal build-up of system pressure and is typically installed between large secondary regulators and burners to provide high capacity relief. However, this series of pressure relief valves is designed for pressure control and is not suitable for use as an ASME safety relief valve.