Slide valves Type 3111 (normally closed) and 3115 (normally open) are pilot-operated, three port, two position valves with a spring-return action. Manifold mounted versions are also available.

A major feature of the valve design is elimination of the continuous leakage which is characteristic of conventional lapped-face spool valves. The valve incorporates special high pressure seals which prevent leakage.

The valve slide (which can be supplied either normally closed or normally open) has a ‘block before bleed’ action. In a normally closed valve, for example, this means that the tank port is isolated before pressure and service ports are interconnected.

The valve body has a fourth connection (port 2) for a pressure gauge. If this port is not used, it must be sealed with a 1/4" NPT plug (not supplied with the valve).

Performance curve

Materials

Predominantly 316 stainess steel and CA104 aluminium bronze with seals of fluoroelastomers and PTFE materials, ensure high corrosion resistance and comply with NACE Standard MR-01-75 (latest revision as applicable).

Operating parameters

Working pressure	690 bar (10,000 psi) max.
Pilot pressure – minimum	4.5 bar (65 psi)
Pilot pressure – maximum	17.2 bar (250 psi)
Operating media – main slide	Mineral oils, water, water-glycol mixtures
Operating media – pilot section	Air, natural and sour gases or any of the main slide media above.
Recommended filtration	25 micron
Connections	1/4"NPT F all ports
Flow rate, nominal	27 litres/min (6 imp galls/min)
Pressure drop	See performance curve
Working temperature – standard	–20°C to + 130°C
Working temperature – arctic	Available on request
Weight	3Kg

Port assignments

Port	Valve 3111	Valve 3115