Admin at 03:45, 21 January 2013

2013-01-21T03:45:16Z

← Older revision		Revision as of 21:45, 20 January 2013
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	[[Category:Valves]]{{Knoppen}}		[[Category:Valves]]{{Knoppen}}
	[[File:~~Gates~~.~~jpg~~\|thumb\|right\|~~Gates~~]]		[[File:Gate valves.gif\|thumb\|right\|Gate Valves]]
	'''~~Gate~~''' or ~~gateway~~ is a ~~point~~ of ~~entry to~~ a ~~space enclosed by walls~~, or a ~~moderately sized opening in some sort~~ of ~~fence~~. ~~Gates may~~ prevent ~~or control~~ the ~~entry or exit~~ of ~~individuals~~, or they ~~may be merely decorative~~. ~~Other terms for~~ gate ~~include yett and port~~. ~~The word derives from~~ the ~~old Norse gata~~, ~~meaning road or~~ path, and ~~originally referred~~ to the ~~gap~~ in the ~~wall or fence~~, ~~rather than the barrier which closed it~~.		[[File:Gate valves1.gif\|thumb\|right\|Gate Valves]]
			'''Gates''' or [[Gate Valves]], also known as a sluice valve, is a valve that opens by lifting a round or rectangular gate or wedge out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar, so gate valves are often used when a straight-line flow of fluid and minimum restriction is desired. The gate faces can form a wedge shape or they can be parallel. Gate valves are primarily used to permit or prevent the flow of liquids, but typical gate valves shouldn't be used for regulating flow, unless they are specifically designed for that purpose. Because of their ability to cut through liquids, gate valves are often used in the petroleum industry. For extremely thick fluids, a specialty valve often known as a knife valve is used to cut through the liquid.On opening the gate valve, the flow path is enlarged in a highly nonlinear manner with respect to percent of opening. This means that flow rate does not change evenly with stem travel. Also, a partially open gate disk tends to vibrate from the fluid flow. Most of the flow change occurs near shutoff with a relatively high fluid velocity causing disk and seat wear and eventual leakage if used to regulate flow. Typical gate valves are designed to be fully opened or closed.When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low friction loss.

	~~A gate may have~~ a ~~latch to keep it from swinging and~~ a ~~lock for security~~. ~~Larger gates can be used for~~ a ~~whole building,~~ such as a ~~castle or fortified town~~, or the ~~actual doors that block entry through~~ the ~~gatehouse~~. ~~Today, many gate doors~~ are ~~opened by an automated gate operator~~.		Gate valves are characterised as having either a rising or a nonrising stem. Rising stems provide a visual indication of valve position because the stem is attached to the gate such that the gate and stem rise and lower together as the valve is operated. Nonrising stem valves may have a pointer threaded onto the upper end of the stem to indicate valve position, since the gate travels up or down the stem on the threads without raising or lowering the stem. Nonrising stems are used underground or where vertical space is limited.

			Bonnets provide leak proof closure for the valve body. Gate valves may have a screw-in, union, or bolted bonnet. Screw-in bonnet is the simplest, offering a durable, pressure-tight seal. Union bonnet is suitable for applications requiring frequent inspection and cleaning. It also gives the body added strength. Bolted bonnet is used for larger valves and higher pressure applications.

			Another type of bonnet construction in a gate valve is pressure seal bonnet. This construction is adopted for [[Valves]] for high pressure service, typically in excess of 15 MPa (2250 psi). The unique feature about the pressure seal bonnet is that the body-bonnet joints seals improves as the internal pressure in the valve increases, compared to other constructions where the increase in internal pressure tends to create leaks in the body-bonnet joint.
			Gate valves may have flanged ends which are drilled according to pipeline compatible flange dimensional standards. Gate valves are typically constructed from cast iron, ductile iron, cast carbon steel, gun metal, stainless steel, alloy steels, and forged steels.


	==~~Types~~==		==Major disadvantages of a gate valve==
	~~Types of gates include:~~		* It is not suitable for throttling applications.
	* ~~Baby gate~~		* It is prone to vibration in the partially open state.
	* ~~City gate~~		* It is more subject to seat and disk wear than a globe valve.
	* ~~Hampshire gate~~		* Repairs, such as lapping and grinding, are generally more difficult to accomplish.
	* Kissing gate
	* Lych gate
	* ~~Torii~~
	* Turnstile
	* Judas Gate - A small door within a larger door




	==Sources==		==Sources==
	[http://en.wikipedia.org/wiki/~~Gate~~ Wikipedia Gate]		[http://en.wikipedia.org/wiki/Gate_valve Wikipedia Gate valve]

Kodiyath at 19:20, 13 January 2013

2013-01-13T19:20:48Z

← Older revision		Revision as of 13:20, 13 January 2013
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	[[Category:Valves]]{{Knoppen}}		[[Category:Valves]]{{Knoppen}}
	~~<noinclude><!------------------------------------------------~~		[[File:Gates.jpg\|thumb\|right\|Gates]]
	* READ THIS FIRST		'''Gate''' or gateway is a point of entry to a space enclosed by walls, or a moderately sized opening in some sort of fence. Gates may prevent or control the entry or exit of individuals, or they may be merely decorative. Other terms for gate include yett and port. The word derives from the old Norse gata, meaning road or path, and originally referred to the gap in the wall or fence, rather than the barrier which closed it.
	* Only edit this page if you can ~~improve~~ the ~~content~~.
	* ~~Improper use of this page will lead to permanent banning.~~		A gate may have a latch to keep it from swinging and a lock for security. Larger gates can be used for a whole building, such as a castle or fortified town, or the actual doors that block entry through the gatehouse. Today, many gate doors are opened by an automated gate operator.
	* ~~Please do not edit the sponsored link on the top right corner.~~
	* ~~Please start editing this page after the /noinclude~~
	* -~~------------------------------------------------><~~/~~noinclude>~~
	~~This page is still empty~~. ~~If you know something about this product, please share your knowledge with others~~.
			==Types==
			Types of gates include:
			* Baby gate
			* City gate
			* Hampshire gate
			* Kissing gate
			* Lych gate
			* Torii
			* Turnstile
			* Judas Gate - A small door within a larger door




			==Sources==
			[http://en.wikipedia.org/wiki/Gate Wikipedia Gate]

Admin: Created page with "Category:Valves{{Knoppen}}

Gates - Revision history

Admin at 03:45, 21 January 2013

Kodiyath at 19:20, 13 January 2013

Admin: Created page with "Category:Valves{{Knoppen}}