Opening time - Revision history

Benstern: added links

2008-06-01T13:08:59Z

added links

← Older revision		Revision as of 08:08, 1 June 2008
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	Opening time is the length time it takes for any given valve to move from the fully closed position to the position allowing the maximum possible volume of gas to flow through. This time period is typically measured in milliseconds, and as expected is most important when the barrel dwell time (the length of time it takes for the projectile to transit the barrel) is low. The approximate opening time of some valves:		Opening time is the length time it takes for any given [[valve]] to move from the fully closed position to the position allowing the maximum possible volume of gas to flow through. This time period is typically measured in milliseconds, and as expected is most important when the [[barrel]] dwell time (the length of time it takes for the projectile to transit the barrel) is low. The approximate opening time of some valves:
	* [[Burst disk]]s Practically instant... most likely under a millisecond.		* [[Burst disk]]s Practically instant... most likely under a millisecond.
	* Pilot operated valves ([[diaphragm valve]]s, [[piston valve]]s): 3-5ms.		* [[Pilot]] operated valves ([[diaphragm valve]]s, [[piston valve]]s): 3-5ms.
	* [[Ball valve]]s: about 100 ms hand-actuated, maybe 20-30 ms spring-actuated.		* [[Ball valve]]s: about 100 ms hand-actuated, maybe 20-30 ms spring-actuated.

	~~The~~ [[GGDT]] will give you a graph of your valve opening. (valve position vs. time or projectile position)		[[GGDT]] will give you a graph of your valve opening. (valve position vs. time or projectile position)

	You can estimate the needed dwell time for a particular gun if you have an estimate of the barrel dwell time. As a rough estimate, assume the average speed in the barrel is one half the desired muzzle velocity. The time it takes for the projectile to transit the barrel is the barrel length divided by this half muzzle velocity. For example, assume you hope the gun will fire at 600 FPS and it has a three foot barrel, the barrel dwell time is about;		You can estimate the needed dwell time for a particular gun if you have an estimate of the barrel dwell time. As a rough estimate, assume the average speed in the barrel is one half the desired [[muzzle velocity]]. The time it takes for the projectile to transit the barrel is the barrel length divided by this half muzzle velocity. For example, assume you hope the gun will fire at 600 FPS and it has a three foot barrel, the barrel dwell time is about;

	(3 feet)/[(600 FPS)(0.5)] = 10 milliseconds		(3 feet)/[(600 FPS)(0.5)] = 10 milliseconds

BC Pneumatics at 19:53, 31 May 2008

2008-05-31T19:53:12Z

← Older revision		Revision as of 14:53, 31 May 2008
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	To get the most out of your gun you would like the valve opening time to be significantly less than the barrel dwell time. In this case, a valve opening time of less than perhaps 3 ms would be a good target.		To get the most out of your gun you would like the valve opening time to be significantly less than the barrel dwell time. In this case, a valve opening time of less than perhaps 3 ms would be a good target.

	It is unclear as to what the opening time is when the valve [[honking\|honks]], as this involves opening and closing rapidly - should one measure it from beginning of opening to end of honking, or from beginning to the most open part of the first vibration? Or, does the [[honking]] occur only after the projectile has left the barrel?

	[[category:valves]]		[[category:valves]]

BC Pneumatics: Jazzed up introductory paragraph

2008-05-31T19:51:44Z

Jazzed up introductory paragraph

← Older revision		Revision as of 14:51, 31 May 2008
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	"Opening time" is the time it takes a valve to ~~open~~, and as expected, is most important when the barrel dwell time (the length of time it takes for the projectile to transit the barrel) is low. The approximate opening time of some valves:		Opening time is the length time it takes for any given valve to move from the fully closed position to the position allowing the maximum possible volume of gas to flow through. This time period is typically measured in milliseconds, and as expected is most important when the barrel dwell time (the length of time it takes for the projectile to transit the barrel) is low. The approximate opening time of some valves:
	* [[Burst disk]]s Practically instant... most likely under a millisecond.		* [[Burst disk]]s Practically instant... most likely under a millisecond.
	* Pilot operated valves ([[diaphragm valve]]s, [[piston valve]]s): 3-5ms.		* Pilot operated valves ([[diaphragm valve]]s, [[piston valve]]s): 3-5ms.

Jimmy101: expanded the relationship between barrel dwell time and valve opening time

2007-11-15T18:10:58Z

expanded the relationship between barrel dwell time and valve opening time

← Older revision		Revision as of 13:10, 15 November 2007
Line 1:		Line 1:
	"Opening time" is the time it takes a valve to open, and as expected, is most important when the barrel dwell time is low. The approximate opening time of some valves:		"Opening time" is the time it takes a valve to open, and as expected, is most important when the barrel dwell time (the length of time it takes for the projectile to transit the barrel) is low. The approximate opening time of some valves:
	* [[Burst disk]]s Practically instant... most likely under a millisecond.		* [[Burst disk]]s Practically instant... most likely under a millisecond.
	* Pilot operated valves ([[diaphragm valve]]s, [[piston valve]]s): 3-5ms.		* Pilot operated valves ([[diaphragm valve]]s, [[piston valve]]s): 3-5ms.
	* [[Ball valve]]s: about 100 ms hand-actuated, maybe 20-30 spring-actuated.		* [[Ball valve]]s: about 100 ms hand-actuated, maybe 20-30 ms spring-actuated.

	The [[GGDT]] will give you a graph of your valve opening. (valve position vs. time or projectile position)		The [[GGDT]] will give you a graph of your valve opening. (valve position vs. time or projectile position)

	~~This author~~ is ~~confused~~ as to what the ~~number~~ is when the valve [[honking\|honks]], as this involves opening and closing rapidly - should one measure it from beginning of opening to end of honking, or from beginning to the most open part of the first vibration?		You can estimate the needed dwell time for a particular gun if you have an estimate of the barrel dwell time. As a rough estimate, assume the average speed in the barrel is one half the desired muzzle velocity. The time it takes for the projectile to transit the barrel is the barrel length divided by this half muzzle velocity. For example, assume you hope the gun will fire at 600 FPS and it has a three foot barrel, the barrel dwell time is about;

			(3 feet)/[(600 FPS)(0.5)] = 10 milliseconds

			To get the most out of your gun you would like the valve opening time to be significantly less than the barrel dwell time. In this case, a valve opening time of less than perhaps 3 ms would be a good target.

			It is unclear as to what the opening time is when the valve [[honking\|honks]], as this involves opening and closing rapidly - should one measure it from beginning of opening to end of honking, or from beginning to the most open part of the first vibration? Or, does the [[honking]] occur only after the projectile has left the barrel?

	[[category:valves]]		[[category:valves]]

Saladtossser: spelling

2007-02-25T01:59:53Z

spelling

← Older revision		Revision as of 20:59, 24 February 2007
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	"Opening time" is the time it takes a valve to open, and as expected, is most important when the barrel dwell time is low. The approximate opening time of some valves:		"Opening time" is the time it takes a valve to open, and as expected, is most important when the barrel dwell time is low. The approximate opening time of some valves:
	* [[Burst disk]]s ~~Practicaly~~ instant... most likely under a millisecond.		* [[Burst disk]]s Practically instant... most likely under a millisecond.
	* Pilot operated valves ([[diaphragm valve]]s, [[piston valve]]s): 3-5ms.		* Pilot operated valves ([[diaphragm valve]]s, [[piston valve]]s): 3-5ms.
	* [[Ball valve]]s: about 100 ms hand-actuated, maybe 20-30 spring-actuated.		* [[Ball valve]]s: about 100 ms hand-actuated, maybe 20-30 spring-actuated.

GalFisk: typo

2007-01-06T10:00:51Z

typo

← Older revision		Revision as of 05:00, 6 January 2007
Line 1:		Line 1:
	"Opening time" is the time it takes a valve to open, and as expected, is most important when the barrel dwell time is low. The approximate opening time of some valves:		"Opening time" is the time it takes a valve to open, and as expected, is most important when the barrel dwell time is low. The approximate opening time of some valves:
	* [[Burst disk]]s Practicaly instant... most likely under a millisecond.		* [[Burst disk]]s Practicaly instant... most likely under a millisecond.
	* Pilot operated valves ([[~~diaphram~~ valve]]s, [[piston valve]]s): 3-5ms.		* Pilot operated valves ([[diaphragm valve]]s, [[piston valve]]s): 3-5ms.
	* [[Ball valve]]s: about 100 ms hand-actuated, maybe 20-30 spring-actuated.		* [[Ball valve]]s: about 100 ms hand-actuated, maybe 20-30 spring-actuated.

GalFisk: +cat, sp

2005-10-24T14:41:57Z

+cat, sp

← Older revision		Revision as of 09:41, 24 October 2005
Line 6:		Line 6:
	The [[GGDT]] will give you a graph of your valve opening. (valve position vs. time or projectile position)		The [[GGDT]] will give you a graph of your valve opening. (valve position vs. time or projectile position)

	This author is confused as to what the number is when the valve [[honking\|honks]], as this involves opening and closing rapidly - should one measure it from ~~begining~~ of opening to end of honking, or from ~~beginging~~ to the most open part of the first vibration?		This author is confused as to what the number is when the valve [[honking\|honks]], as this involves opening and closing rapidly - should one measure it from beginning of opening to end of honking, or from beginning to the most open part of the first vibration?

			[[category:valves]]

Boilingleadbath: removed by questionable info,

2005-10-21T22:51:39Z

removed by questionable info,

← Older revision		Revision as of 17:51, 21 October 2005
Line 1:		Line 1:
	"Opening time" is the time it takes a valve to open, and as expected, is most important when the barrel dwell time is low. The approximate opening time of some valves:		"Opening time" is the time it takes a valve to open, and as expected, is most important when the barrel dwell time is low. The approximate opening time of some valves:
	* [[Burst disk]]s Practicaly instant... most likely under a millisecond.		* [[Burst disk]]s Practicaly instant... most likely under a millisecond.
	* [[~~Diaphram~~ valve]]s ~~About 3 ms~~, ~~with a decent~~ [[~~pilot valve]].~~		* Pilot operated valves ([[diaphram valve]]s, [[piston valve]]s): 3-5ms.
	* [[Barrel-sealing piston valve]]s ~~just a tiny bit longer.~~		* [[Ball valve]]s: about 100 ms hand-actuated, maybe 20-30 spring-actuated.
	* [[Chamber-sealing piston valve]]s A bit longer yet, but still under 4-~~5 ms~~.
	* [[Ball valve]]s about 100 ms hand-actuated, maybe 20-30 spring-actuated.		The [[GGDT]] will give you a graph of your valve opening. (valve position vs. time or projectile position)

	This author is confused as to what the number is when the valve [[honking\|honks]], as this involves opening and closing rapidly - should one measure it from begining of opening to end of honking, or from beginging to the most open part of the first vibration?		This author is confused as to what the number is when the valve [[honking\|honks]], as this involves opening and closing rapidly - should one measure it from begining of opening to end of honking, or from beginging to the most open part of the first vibration?

Boilingleadbath at 22:40, 21 October 2005

2005-10-21T22:40:16Z

New page

"Opening time" is the time it takes a valve to open, and as expected, is most important when the barrel dwell time is low. The approximate opening time of some valves:
* [[Burst disk]]s Practicaly instant... most likely under a millisecond.
* [[Diaphram valve]]s About 3 ms, with a decent [[pilot valve]].
* [[Barrel-sealing piston valve]]s just a tiny bit longer.
* [[Chamber-sealing piston valve]]s A bit longer yet, but still under 4-5 ms.
* [[Ball valve]]s about 100 ms hand-actuated, maybe 20-30 spring-actuated.

This author is confused as to what the number is when the valve [[honking|honks]], as this involves opening and closing rapidly - should one measure it from begining of opening to end of honking, or from beginging to the most open part of the first vibration?