A Complete Guide To Gate Valve
The gate valve is the most common shut-off valve. Unlike ball valves, they are not quarter-turn devices; instead, they close and open through revolutions of the hand wheel.
Used in wastewater plants, power plants and process systems, the threaded system of the gate valves give them an advantage over the quarter turn system of the ball and butterfly valve in large applications.
Fluid through gate valves experiences only minimal pressure drop as gate valves allow total flow through its passage when fully open.
This post discusses the functions, symbols, advantages and disadvantages, types, and other essential things you need to know about the gate valve.
What is A Gate Valve?
Gate valves can also be called sluice valves or knife valves. They are control valves that allow or restrict the flow of media completely. Gate valves use a flat gate to close off flow between pipe flanges.
A gate valve, being a full port valve, has an equal diameter to the pipe through which the fluid passes. Hence, unlike butterfly valves, gate valves minimise pressure losses in the fluid when fully open. Also, because of the equal pipe and valve diameters, gate valves allow for the movement of pigs within the pipe for cleaning and inspection operations.
While butterfly valves can be used in flow regulation and on-off services, gate valves should only be used in on-off services as blocking valves and also to allow fluid flow. They should not be used in throttling.
Because of their uncomplicated construction and capability to be used in different low-pressure applications, gate valves are one of the most common valves in the industry.
Gate Valve Symbol
The gate valve symbol is composed of two triangles meeting at a point. A vertical line is inserted between the triangles, and solid horizontal lines extend from the opposite sides of the triangle.
The vertical line indicates the blocking operation of the gate valve, and the horizontal lines show that the valve has a two-way function in on-off applications.
The gate valve symbol used in piping and instrumentation diagrams (P&ID) is a modification of the valve symbol, which is the gate valve symbol without the vertical line between the triangles.
The three isometric symbols in the diagram indicate symbols for butt-welding end connections, flanged ends, and socket ends connections.
Size 1/2-16 inch Material Stainless Steel Color Grey Feature Blow-Out-Proof, Casting Approved Pressure High End Connection Flanged
Gate & Globe Valves, Ball Valves and Manifold
Valves, Gate valve
MATIREAL - CAST IRON / CAST STEEL / STAINLESS STEEL 304/316/316L / WCB BALL - STAINLESS STEEL 304 / 316//316L STEAM - STAINLESS STEEL 304/316 GLAND NUT - 304 / 316 STAINLESS STEEL SEAT - PTFE/CTFE/GTFE SIZE - 1/4 INCH TO 4 INCH
MATIREAL - CAST IRON / CAST STEEL / STAINLESS STEEL 304/316/316L / WCB BALL - STAINLESS STEEL 304 / 316//316L STEAM - STAINLESS STEEL 304/316 GLAND NUT - 304 / 316 STAINLESS STEEL STUD NUT - STAINLESS STEEL 304 SEAT - PTFE/CTFE/GTFE
MATERIAL - CAST IRON / CAST STEEL / WCB / STAINLESS STEEL 3O4/316/316L BALL - STAINLESS STEEL 304 / 316 STEAM - STAINLESS STEEL 304/316/ GLAND NUT - STAINLESS STEEL 304/316 LEVER - STAINLESS STEEL 304 SEAT - PTFE / CTFE / GTFE STUD NUT - STAINLEES STEEL 304
Screwed End Gate Valve Main features * Bolted body-bonnet design for valves up to Class 800, 1500, 2500, 4500. Valves with welded bonnet also available on request * Screwed with a seal-welded body-bonnet design for valves of Class 1500,2500, 4500. * Bellows-sealed Gate and Globe valves available in Class 800 * Bolted body-bonnet joints provided with spiral-wound stainless steel gasket and graphite filler for maximum protection against leaks * Die-formed graphite inner packing rings and braided graphite end rings with Inconel wire reinforcement and corrosion inhibitor * T-head stem-disc connection of gate valve fully meets strength requirements of API 602 and API 598 * Rolled ACME thread on stem for smooth operation * Tapered shoulder on the stem for back seating * Self-aligning type gland assembly with stud-and-nut tightening * Integral hard-faced body seat for globe and check valves * Spring-loaded disc on check valves suitable for no horizontal applications too * Gate and globe valves can be offered with electrical actuators * Austenitic SS forging for body and bonnet of Cryogenic valves, resulting in excellent impact strength, minimal heat loss and resistance to corrosion * Valves can be offered to NACE MR-0175 and other special NACE requirements
Fig. No. G1000 Size: DN15-DN50 Design Standard: EN1074-1.2 Internal & External Coating : DIN30677-2 Threaded End according to BSPP, NPT Working Pressure: PN10, PN16. Hydralic Test according to EN12266-1, ISO5208 Material conform to EN-GJS500-7.
Fig. No. G1000 Size: DN15-DN50 Design Standard: EN1074-1.2 Internal & External Coating : DIN30677-2 Threaded End according to BSPP, NPT Working Pressure: PN10, PN16. Hydralic Test according to EN12266-1, ISO5208 Material conform to EN-GJS500-7.
