Product Overview

The DANIEL 762 is a gas loaded, direct acting back pressure and surge relief control valve for liquid pipelines. The valve is normally closed and opens on rising inlet pressure: line pressure on the nose of the piston is balanced against nitrogen pressure plus spring force, and the integral oil reservoir on the cylinder head acts as a movable barrier so that nitrogen never reaches the piston seals. Because the valve is not pilot operated, opening is almost unrestricted and response to a pressure surge is immediate, while closing speed is set by the fixed orifice in the check valve. The balanced piston design gives linear control characteristics, positive shut-off and high flow capacity, and all internals including cylinder, piston and seat ring are removed as a cartridge assembly without breaking the line connections. Sizes NPS 2 to 16 in ANSI Class 150 to 600.

Product Features

• Nitrogen loaded, direct acting design, no pilots, no diaphragms and no stuffing boxes

• Balanced piston with linear control characteristics, positive shut-off and high flow capacity

• Exceptionally fast opening for pipeline surge relief, closing speed set by the check valve orifice

• Integral oil reservoir keeps nitrogen away from the piston seals, so no gas is consumed in service

• Cartridge internals, cylinder, piston and seat ring are removed without disturbing the line connections

Typical Applications

Liquid pipeline pressure and surge relief, back pressure control at pump stations and metering stations, pump station by-pass and minimum back pressure holding on product lines.

Selection Notes

Sizing depends on the relief flow, the set pressure and the nitrogen supply pressure, so please give line size, ANSI class, product and flow rate. Higher than Class 600 is available on request. Send the data sheet and we will confirm the model and delivery.