Introduction

Figure 1. 1805 Series Relief Valve

The 1805 Series are diaphragm relief valves that protect piping downstream of a regulator from excessive pressure. It is usually installed between a First and Second-Stage regulator or in the downstream line from a high-pressure regulator used for Final-Stage service. Its internal parts can be removed without taking the body out of the line.

Relief pressures range from 5 to 125 psi (0,34 to 8,6 bar). Maximum pressure including buildup is 150 psi (10,3 bar).

Features

• Tight Shutoff
• Simple Adjustment
• Easy Maintenance
• Complete Venting

Relief Pressure Setting
30 psig (2,1 bar)

Relief Adjustment Range
See Table 1

Temperature Capabilities
-20° to 150°F (-29° to 66°C)

Body Size and End Connection Style
See Table 1

Additional Technical Data
For more technical information contact your Fisher Distributor or refer to LP-31 Equipment Buyer’s Guide.

Figure 2. Dimensions

Figure 3. 1805 Series Operational Schematic