FISHER 289H-49 relief Valves or Backpressure Regulators

FISHER 289H-49 is a 289 series pressure relief valve or back pressure regulator, a spring loaded throttling relief valve that can be used as a downstream pressure regulator to prevent overpressurization of a system. The following is a description:

Connection Size: Available in 1NPT and 2NPT sizes with NPT threaded connections for ease of installation and removal, enabling connection to a wide range of piping systems.

Pressure parameters

Maximum Allowable Pressure Relief (Inlet) Pressure: Typically 100 psig/6.9 bar, but the 289H model is unique in that the maximum pressure relief (inlet) pressure is 25 psig/1.7 bar.

Pressure Relief Setting Pressure Range: Typically 5wc to 50psig (25mbar to 3.5bar), with models 289H - 49 having a 15 - 50PSI (1.0 - 3.4bar) bleed pressure, adjustable by spring setting.

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: 4lb/2kg for 1NPT, 15lb/7kg for 2NPT.

Other features: Features a large valve diaphragm area for high sensitivity, ideal for low-pressure settings. Its smooth throttling operation minimizes pressure shock in the system during relief operation. However, this series of pressure relief valves is designed for pressure control and is not suitable for use as an ASME safety relief valve.