FISHER 289L Spring-Loaded Throttling Relief Valve 3/4 and 1 NPT 25-99 mbar
Product Overview
The Fisher Type 289L is a spring-loaded throttling relief valve protecting downstream systems from overpressure. The Type 289L belongs to the Fisher 289 series of spring-loaded throttling relief valves for downstream overpressure protection.
Key Features
Throttling relief action minimizes pressure surges in the downstream system
Pitot tube booster delivers high relief capacity with minimal pressure buildup
3/4 and 1 NPT sizes with relief settings of 25 to 99 mbar (10 to 40 in. w.c.)
Aluminum body with NBR diaphragm acting as the disk for tight shutoff
Large diaphragm area provides sensitive control at low pressure settings
Typical Applications
Overpressure venting on natural gas, LPG and air systems downstream of pressure regulators in distribution and industrial pipelines.
Selection Guide
Choose the spring range that covers your required relief set point; both 3/4 and 1 NPT inlet connections are available. Contact us with your set point and line size for sizing help.










