Types 3111 and 3115
Slide valves



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).

Construction 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).

These slide valves conform to Directive 94/9/EC relating to equipment intended for use in potentially explosive atmospheres and is ATEX (ATmosphere EXplosible) certified.
Marshalsea Hydraulics has been assessed by SGS Société Générale de Surveillance SA and certified as meeting the requirements of ISO 9001:2000 for the design, development, manufacture and servicing of hydraulic pumps, relief valves and intensifiers.

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" NPTF all ports.
Flow rate, nominal 27 litres/min (6 imp galls/min).
Working temperature – standard –20°C to + 130°C.
Working temperature – arctic Available on request.