289 Series Relief Valves / Backpressure Regulators

The 289 Series relief valves are spring-loaded throttling relief valves used downstream of pressure regulators to protect the downstream system from overpressure. A smooth throttling action minimizes pressure surges in the system during relief operation. The 289 Series relief valves are ideal for low-pressure settings due to the increased sensitivity provided by a large diaphragm area. The 289 Series relief valves are designed for pressure control; they are not ASME safety relief valves.

Features

High Flow Rates
Small Size
Reliability Due to Simplicity
Tight Shutoff
Throttling Type Relief

Body Sizes and End Connection Styles

Type 289A: 1/4 FNPT
Type 289H: 1, 2 FNPT
Type 289HH: 1 FNPT
Type 289L: 3/4, 1 FNPT

Maximum Allowable Relief (Inlet) Pressure
100 psig (6,9 bar)

Relief Set Pressure Ranges

Type 289A - Zinc:
- 3 to 13 psi (0,21 to 0,90 bar)
- 11 to 22 psi (0,76 to 1,5 bar)
Type 289H - Cast iron:
- 7 to 18-inches w.c. (17 to 45 mbar)
- 0.5 to 2.25 psi (0,03 to 0,15 bar)
- 1.75 to 7 psi (0,12 to 0,48 bar)
- 4 to 10 psi (0,28 to 0,69 bar)
Type 289H - Aluminum:
- 1 to 4.5 psi (0,07 to 0,31 bar)
- 4 to 15 psi (0,28 to 1,0 bar)
- 10 to 20 psi (0,69 to 1,4 bar)
- 15 to 50 psi (1,0 to 3,5 bar)
Type 289HH - Aluminum:
- 45 to 75 psi (3,1 to 5,2 bar)
Type 289L - Aluminum:
- 12 to 40-inches w.c. (30 to 99 mbar)
- 10 to 18-inches w.c. (25 to 45 mbar)

Pressure Registration
Internal

Temperature Capabilities

Nitrile (NBR) and Neoprene (CR) Elastomers: -20 to 150°F (-29 to 66°C)
Fluorocarbon (FKM): 20 to 300°F (-7 to 149°C) / Available with Types 289H and 289HH only

Approximate Weights

Type 289A and 289U: 0.75 Pounds (0,3 kg)
Type 289H:
- 1 NPT - 4 Pounds (2 kg)
- 2 NPT - 15 Pounds (7 kg)
Type 289HH: 4 Pounds (2 kg)
Type 289L: 15 Pounds (7 kg)