Fisher 289 Series Relief Valves or Backpressure Regulators

The following is an introduction to the Fisher 289 series safety valve and common models:

The Fisher 289 series is a spring-loaded throttling pressure relief valve that balances the system pressure through the elastic force of the spring. When the system pressure exceeds the set relief pressure, the spring is compressed, the valve opens, and the excess pressure is released to protect the downstream system from damage caused by excessive pressure; when the pressure returns to the normal range, the spring resets and the valve closes.

Technical parameters of Fisher 289 series safety valve

Inlet pressure: up to 7bar.

Set relief pressure: range 0.01-5.17bar.

Relief volume: 0-3200Nm³/h.

Working temperature: -29-66℃.

Connection size: 1/4, 3/4, 1, 2” NPT threaded connection.

Functional features of Fisher 289 series safety valve

Throttling pressure relief: Smooth and continuous adjustment can achieve throttling pressure relief, which can effectively prevent sudden pressure changes during the pressure reduction process and minimize the pressure shock in the system.

High sensitivity: The use of a larger valve diaphragm area makes the valve more sensitive to pressure changes, especially suitable for low pressure settings.

Large flow: With the help of a pitot tube booster device (except 1/4NPT Dimensions), can achieve high flow pressure relief with minimal pressure rise, can meet the pressure relief needs under different working conditions.

High reliability: simple internal structure, using a single internal component, reducing the possibility of mechanical failure, improving the reliability and stability of the valve.

Easy installation: compact structure, small size, and can be installed in any position, easy to install and use in different spaces and environmental conditions.

Application areas: commonly used in the transportation and control systems of various gases such as natural gas, artificial coal gas, liquefied petroleum gas, air, etc., suitable for various industrial and civil users, such as gas pressure regulating stations, gas boilers, gas water heaters and other equipment downstream, to provide overpressure protection.

Common models of Fisher 289 series safety valve

289A: 1/4NPT spring-loaded safety valve, relief pressure setting range is 3-22psig (0.21-1.5bar), with two spring ranges.

289H: 1 or 2NPT spring-loaded safety valve type, relief pressure setting range is 1-50psig (0.07-3.4bar). Among them, 1NPT has four spring ranges, namely 7in.w.c. to 10psig (17mbar to 0.69bar), etc.; 2NPT also has four spring ranges. Common specific models are 289H-41 (1-4.5PSI), 289H-42 (4-15PSI), 289H-43 (10-20PSI), 289H-49 (15-50PSI).

289HH: 1NPT spring-loaded safety valve, relief pressure setting range is 45-75psig (3.1-5.2bar), such as 289HH-1.

289L: 3/4 or 1NPT spring-loaded safety valve type, common models such as 289L-21, 1 inch NPT, relief pressure 12-40WC.

289U: 1/4NPT, the specific parameters are different from 289A and other models, but they belong to the same category. 289 Series, for specific pressure control applications.