Slab Gate Valve - An Overview

What is slab gate valve?

Slab gate valve is comprised of a single gate unit which raises and lowers between two seat rings. Due to the fact that the gate slides between the seats, slab gate valves are suitable for the medium with suspended particles. The sealing surface of slab gate valves is virtually self-positioned and is not damaged by the thermal deformation of the body. Even if the valve is closed in a cold state, the hot elongation of the stem does not overload the sealing surface, and slab gate valves without diversion holes do not require high precision in the closing position of the gate. When the valve is fully open, the bore through is smooth and linear, the flow resistance coefficient is minimal, piggable and no pressure loss. 

pros&cons of slab gate valve

Slab gate valves also have some disadvantages: when the medium pressure is low, the metal sealing surface may not seal completely, instead, when the medium pressure is too high, the highly-frequency opening and closing may make the sealing surface wear too much when there is no medium or lubrication. Another drawback is that a circular gate that moves horizontally on a circular channel controls flow effectively only when it is at 50% of the valve's closed position.

Slab gate valves applications 

Single or double-disc slab gate valves are suitable for oil and gas pipelines with DN50-DN300, class150-900/ PN1.0-16.0 Mpa, operating temperature -29 | 121 ℃. In the case of pipeline with piggable design, use a rising stem gate valve with a diversion hole. The slab gate valve with a diversion hole with a dark rod floating seat is suitable for oil and gas recovery wellhead device. The product oil pipeline and storage equipment shall use a single gate or double gate flat gate valves without diversion holes.

Here is an article about tips you should considerate before request a quote to gate valve manufacturer.