Steam Engine Build/Valve Cover - Revision history

Mjn at 12:56, 2 July 2011

2011-07-02T12:56:26Z

← Older revision		Revision as of 12:56, 2 July 2011
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	==2. Initial Valve Cover Plate Fabrication==		==2. Initial Valve Cover Plate Fabrication==

	# Cut a ~~square 8~~.5" ~~on a side~~ from half inch cast iron plate.		# Cut a rectangle 7.5" by 9.5" from half inch cast iron plate.
	# Cut a rectangular hole 1.5" by 4.0" centered in the plate.		# Cut a rectangular hole 1.5" by 5.0" centered in the plate.
	# Drill eight half inch bolt holes top, bottom, left, right, and all four corners offset from the sides of the plate by 1.0".		# Drill eight half inch bolt holes top, bottom, left, right, and all four corners offset from the sides of the plate by 0.5".
	# Weld the valve holder to the valve cover plate.		# Weld the valve holder to the valve cover plate.

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	The steam vent can then be used to pressurize the steam chest (gap between the valve cover and the cylinder end cap). Soap brushed over the welds should reveal leaks. For additional testing, immerse the test assembly into a pan of oil and repeat the pressure test looking for bubbles formed. Assuming a source of air pressure equal to estimated steam pressure (150psi), this will verify steam-tight welds.		The steam vent can then be used to pressurize the steam chest (gap between the valve cover and the cylinder end cap). Soap brushed over the welds should reveal leaks. For additional testing, immerse the test assembly into a pan of oil and repeat the pressure test looking for bubbles formed. Assuming a source of air pressure equal to estimated steam pressure (150psi), this will verify steam-tight welds.

	~~==4. Drill Valve Holes==~~

	~~(block/plate sub-assembly with valve holes shown)~~

	~~==5. Flange Fabrication==~~

	~~# Cut four rectangular pieces of half inch plate steel 1.0" wide by 8" long.~~
	~~# Weld them to the back of the valve cover plate.~~

	~~==6. Final Valve Cover==~~

	~~(full drawing here)~~

	[[Category:Steam Engine]]		[[Category:Steam Engine]]

Mjn at 12:52, 2 July 2011

2011-07-02T12:52:02Z

← Older revision		Revision as of 12:52, 2 July 2011
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	'''Valve Cover Assembly'''<br>		'''Valve Cover Assembly'''<br>
	[[Image:cad-valve-~~end~~-asmbly-1.png]][[Image:cad-valve-~~end~~-asmbly-1.png]]		[[Image:cad-valve-cover-asmbly-1.png]][[Image:cad-valve-cover-asmbly-2.png]]

	=Drawing=		=Drawing=

Mjn at 12:48, 2 July 2011

2011-07-02T12:48:47Z

← Older revision		Revision as of 12:48, 2 July 2011
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	'''Valve Cover Plate and Mount'''<br>		'''Valve Cover Plate and Mount'''<br>
	[[Image:cad-valve-end-mount.png]]		[[Image:cad-valve-end-mount.png]]

			'''Valve Cover Assembly'''<br>
			[[Image:cad-valve-end-asmbly-1.png]][[Image:cad-valve-end-asmbly-1.png]]

	=Drawing=		=Drawing=

Mjn at 12:28, 2 July 2011

2011-07-02T12:28:58Z

← Older revision		Revision as of 12:28, 2 July 2011
Line 16:		Line 16:

	The design here is slightly different than earlier versions. Previously, a separate mounting bracket was used and is now merged into this element. Also, a flange around the end was eliminated for simplicity. If needed to make a better seal for the steam cabinet, it can be restored.		The design here is slightly different than earlier versions. Previously, a separate mounting bracket was used and is now merged into this element. Also, a flange around the end was eliminated for simplicity. If needed to make a better seal for the steam cabinet, it can be restored.

	~~[[Image:Spec-Valve-Cover-Welds.png]]~~

	The valve cover consists of three sub-parts welded together as shown in the drawing (not to scale) above:		The valve cover consists of three sub-parts welded together as shown in the drawing (not to scale) above:
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	=Drawing=		=Drawing=

			Click on the image to see the drawings full size.

	'''Valve Holder'''<br>		'''Valve Holder'''<br>

Mjn at 12:28, 2 July 2011

2011-07-02T12:28:04Z

← Older revision		Revision as of 12:28, 2 July 2011
Line 36:		Line 36:

	'''Valve Holder'''<br>		'''Valve Holder'''<br>
	[[Image:Spec-Valve-Holder.png~~\|frame~~\|300px]]		[[Image:Spec-Valve-Holder.png\|300px]]

	'''Valve Cover Plate and Mount'''<br>		'''Valve Cover Plate and Mount'''<br>
	[[Image:Spec-Valve-End-Mount.png~~\|frame~~\|300px]]		[[Image:Spec-Valve-End-Mount.png\|300px]]

	=Instructions=		=Instructions=

Mjn at 12:27, 2 July 2011

2011-07-02T12:27:32Z

← Older revision		Revision as of 12:27, 2 July 2011
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	=Drawing=		=Drawing=

	[[Image:Spec-Valve-Holder.png\|~~thumb\|right~~\|300px]]		'''Valve Holder'''<br>
			[[Image:Spec-Valve-Holder.png\|frame\|300px]]

	[[Image:Spec-Valve-End-Mount.png\|~~thumb\|right~~\|300px]]		'''Valve Cover Plate and Mount'''<br>
			[[Image:Spec-Valve-End-Mount.png\|frame\|300px]]

	=Instructions=		=Instructions=

Mjn at 12:21, 2 July 2011

2011-07-02T12:21:46Z

← Older revision		Revision as of 12:21, 2 July 2011
Line 3:		Line 3:
	[[Steam Engine Build Instructions]]		[[Steam Engine Build Instructions]]

	~~[[Image:Valve-Cover.png\|thumb]]~~
	=Description=		=Description=

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	* Holds and aligns the valve springs in place		* Holds and aligns the valve springs in place
	* Shelters the valve springs from steam heat		* Shelters the valve springs from steam heat
	* ~~Steam~~ input vent		* Provides steam to the engine via the steam input vent
	* ~~Bolted~~ to cylinder ~~end cap~~		* Creates a sealed steam chamber by bolting the valve cover to the valve seat and cylinder flange
	* ~~Bolted to~~ mounting bracket		* Provides a mounting bracket to support the steam engine

	Because of the size of the valves and valve springs, the valve cover is quite thick along the engine center line axis. Eventually, this part should be molded in cast iron. To simplify initial fabrication, the valve cover is built up from the three pieces of metal, welded together.		Because of the size of the valves and valve springs, the valve cover is quite thick along the engine center line axis. Eventually, this part should be molded in cast iron. To simplify initial fabrication, the valve cover is built up from the three pieces of metal, welded together.

			The design here is slightly different than earlier versions. Previously, a separate mounting bracket was used and is now merged into this element. Also, a flange around the end was eliminated for simplicity. If needed to make a better seal for the steam cabinet, it can be restored.

	[[Image:Spec-Valve-Cover-Welds.png]]		[[Image:Spec-Valve-Cover-Welds.png]]
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	* Valve Cover Holder		* Valve Cover Holder
	* Valve Cover Plate		* Valve Cover Plate
	* Valve Cover Flange		* Valve Cover Base Flange

			=CAD=

			'''Valve Holder'''<br>
			[[Image:cad-valve-holder-1.png]][[Image:cad-valve-holder-2.png]]

			'''Valve Cover Plate and Mount'''<br>
			[[Image:cad-valve-end-mount.png]]

	=Drawing=		=Drawing=
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	[[Image:Spec-Valve-Holder.png\|thumb\|right\|300px]]		[[Image:Spec-Valve-Holder.png\|thumb\|right\|300px]]

	[[Image:Spec-Valve-~~Cover~~-~~Plate~~.png\|thumb\|right\|300px]]		[[Image:Spec-Valve-End-Mount.png\|thumb\|right\|300px]]

	=Instructions=		=Instructions=

Mjn: Added CAD view.

2011-06-11T12:05:44Z

Added CAD view.

← Older revision		Revision as of 12:05, 11 June 2011
Line 3:		Line 3:
	[[Steam Engine Build Instructions]]		[[Steam Engine Build Instructions]]

			[[Image:Valve-Cover.png\|thumb]]
	=Description=		=Description=

Mjn at 02:13, 4 June 2011

2011-06-04T02:13:02Z

← Older revision		Revision as of 02:13, 4 June 2011
Line 24:		Line 24:

	=Drawing=		=Drawing=

			[[Image:Spec-Valve-Holder.png\|thumb\|right\|300px]]

	[[Image:Spec-Valve-Cover-Plate.png\|thumb\|right\|300px]]		[[Image:Spec-Valve-Cover-Plate.png\|thumb\|right\|300px]]

	~~[[Image:Spec-Valve-Holder.png\|thumb\|right\|300px]]~~

	=Instructions=		=Instructions=
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	==1. Initial Valve Holder Fabrication==		==1. Initial Valve Holder Fabrication==

	~~(instructions here)~~		# Cut a piece of cast iron 2.5" by 5.0" by 3.0"
			# On the 2.5" face, drill two 1.25" dia holes 1.25" from the top and bottom to a depth of 2.5".
			# On the opposite face, drill two 0.5" holes through to the previous 1.25" dia holes.
			# on the 2.5" face, drill one 0.5" hole completely through the valve holder.

	==2. Initial Valve Cover Plate Fabrication==		==2. Initial Valve Cover Plate Fabrication==

	~~(instructions here)~~		# Cut a square 8.5" on a side from half inch cast iron plate.
			# Cut a rectangular hole 1.5" by 4.0" centered in the plate.
			# Drill eight half inch bolt holes top, bottom, left, right, and all four corners offset from the sides of the plate by 1.0".
			# Weld the valve holder to the valve cover plate.

	==3. Weld Test==		==3. Weld Test==

Mjn: Fixing up page name.

2011-06-04T01:52:05Z

Fixing up page name.

New page

{{Category=Steam Engine}}

[[Steam Engine Build Instructions]]

=Description=

The valve cover serves the following functions:
* Holds the valves in place
* Holds and aligns the valve springs in place
* Shelters the valve springs from steam heat
* Steam input vent
* Bolted to cylinder end cap
* Bolted to mounting bracket

Because of the size of the valves and valve springs, the valve cover is quite thick along the engine center line axis. Eventually, this part should be molded in cast iron. To simplify initial fabrication, the valve cover is built up from the three pieces of metal, welded together.

[[Image:Spec-Valve-Cover-Welds.png]]

The valve cover consists of three sub-parts welded together as shown in the drawing (not to scale) above:

* Valve Cover Holder
* Valve Cover Plate
* Valve Cover Flange

=Drawing=

[[Image:Spec-Valve-Cover-Plate.png|thumb|right|300px]]

[[Image:Spec-Valve-Holder.png|thumb|right|300px]]

=Instructions=

==1. Initial Valve Holder Fabrication==

(instructions here)

==2. Initial Valve Cover Plate Fabrication==

(instructions here)

==3. Weld Test==

Welds attaching the block to the plate are critical because they must be absolutely air-tight or steam will escape. Worse, superheated steam will erode steel if it flows through a narrow channel (leak). The best way to test this to fabricate the cylinder valve seat (see [[Steam Engine Build/Cylinder Valve Seats]], but omit milling of the valve seats. This allows the cap to be bolted to the valve cover plate with only the steam vent drilled.

(block/plate sub-assembly for weld test)

The steam vent can then be used to pressurize the steam chest (gap between the valve cover and the cylinder end cap). Soap brushed over the welds should reveal leaks. For additional testing, immerse the test assembly into a pan of oil and repeat the pressure test looking for bubbles formed. Assuming a source of air pressure equal to estimated steam pressure (150psi), this will verify steam-tight welds.

==4. Drill Valve Holes==

(block/plate sub-assembly with valve holes shown)

==5. Flange Fabrication==

# Cut four rectangular pieces of half inch plate steel 1.0" wide by 8" long.
# Weld them to the back of the valve cover plate.

==6. Final Valve Cover==

(full drawing here)

[[Category:Steam Engine]]