Supah-Valve Imitation
Posted: Sat Aug 02, 2008 9:55 am
Well, I was bored last night, again, and decided to draw up this imitation supah valve.
It's a chamber sealing valve, but I designed it in a way to not require specialized tools (like a lathe to cut O-ring grooves and trim down a piston). All that's required is a belt-sander, hacksaw, and other minor tools that everybody should have access to.
The image is below.
The brown is a 3" tee.
The yellow is a 3x2" threaded bushing (3" spigot x 2" FNPT)
The red is a 3x2" slip bushing (3" spigot x 2" slip)
The dark blue is a length of 2" SCH-40
All the black is rubber. Individual parts explained below.
All the gray is steel hardware. Individual parts explained below.
The white part is a 2" endcap.
The green part is some 3" SCH-40.
The light blue is a 3x1.5" slip bushing.
The purple is a 1.5x.75 threaded bushing.
Here's the rundown.
From left to right, the seals (rubber, represented by black), are: chamber sealing gasket (piston face), endcap sealing gasket (seals endcap to test plug), 3" test plug, bumper, and service port sealing gasket (the two are represented as one part in the drawing).
The test plug serves as the piston. As it is tightened, the rubber part expands to fill the pipe, forming a seal that, when lubricated, should work fine as a piston seal. Two test plugs need to be bought, though. Each comes with two metal ends, one larger than the other, to push against the outside of the pipe. All the ends are removed, and one rubber core is reassembled with two of the smaller metal faces, so that the plug will fit all the way inside of the pipe. Some 5/16" threaded rod (same size as the bolt through the original test plug), is used to both tighten the plug and attach the 2" endcap as the sealing extension. An equalization hole is drilled through the endcap and test plug, and the endcap is sealed onto the test plug with a small gasket.
The 3" pipe needs to be sanded down in diameter at the end to fit over the stop in the 3" tee. Don't say "You need a lathe to do that!", because I have done it with a belt sander before to make a barrel-sealer.
Finally, on the matter of the bushings. First, the hex part of the bushings is sanded down to the cylindrical profile of the rest of the bushing. Then, they are trimmed in length. For the top bushing (barrel connection), the end (inside) is trimmed the length of the hex ridge removed. For the left (chamber connection), the end is trimmed the length of the trimmed slip bushing inside, which is itself trimmed to about half the socket depth of the tee.
The 3x1.5" bushing on the right is trimmed to about 1/3 of the tee socket depth. Care needs to be taken to buy a bushing that is of solid construction on the outside, and not ribbed like some, as when you trim these, you will be left with holes (bad). Then, the 3/4" bushing has it's hex removed and trimmed the length of the hex ridge. Both are solvent welded together, but DO NOT solvent weld them into the tee.
For connection into the tee, the bushing assembly is attached by about 8 1/4"-20 machine screws, spaced evenly and, for aesthetics, in one line, not crooked. Before drilling and tapping, assemble the rest of the valve. Then, when you're ready to seal the valve up, place on a hard flat surface with the chamber port down. Place the bushing on top of the service port sealing gasket (about 1/8" neoprene), and then set one or two 25 pound weights on top of it (depending on the hardness of the rubber gasket). While the gasket is depressed, drill and tap the holes for the screws, and then fasten the bushing assembly in place with the machine screws. You are now set.
I drew this drawing roughly to scale (but taking the measurements in hundredths of inches and dividing by four to get the number of pixels), but rounding and approximation were used heavily, so it is best to lift measurements from the parts you yourself order to build this valve. I intended this to be helpful for anybody wanted to build a Supah-valve imitation, and those interested in building chamber-sealing valves without special tooling. Good luck.
It's a chamber sealing valve, but I designed it in a way to not require specialized tools (like a lathe to cut O-ring grooves and trim down a piston). All that's required is a belt-sander, hacksaw, and other minor tools that everybody should have access to.
The image is below.
The brown is a 3" tee.
The yellow is a 3x2" threaded bushing (3" spigot x 2" FNPT)
The red is a 3x2" slip bushing (3" spigot x 2" slip)
The dark blue is a length of 2" SCH-40
All the black is rubber. Individual parts explained below.
All the gray is steel hardware. Individual parts explained below.
The white part is a 2" endcap.
The green part is some 3" SCH-40.
The light blue is a 3x1.5" slip bushing.
The purple is a 1.5x.75 threaded bushing.
Here's the rundown.
From left to right, the seals (rubber, represented by black), are: chamber sealing gasket (piston face), endcap sealing gasket (seals endcap to test plug), 3" test plug, bumper, and service port sealing gasket (the two are represented as one part in the drawing).
The test plug serves as the piston. As it is tightened, the rubber part expands to fill the pipe, forming a seal that, when lubricated, should work fine as a piston seal. Two test plugs need to be bought, though. Each comes with two metal ends, one larger than the other, to push against the outside of the pipe. All the ends are removed, and one rubber core is reassembled with two of the smaller metal faces, so that the plug will fit all the way inside of the pipe. Some 5/16" threaded rod (same size as the bolt through the original test plug), is used to both tighten the plug and attach the 2" endcap as the sealing extension. An equalization hole is drilled through the endcap and test plug, and the endcap is sealed onto the test plug with a small gasket.
The 3" pipe needs to be sanded down in diameter at the end to fit over the stop in the 3" tee. Don't say "You need a lathe to do that!", because I have done it with a belt sander before to make a barrel-sealer.
Finally, on the matter of the bushings. First, the hex part of the bushings is sanded down to the cylindrical profile of the rest of the bushing. Then, they are trimmed in length. For the top bushing (barrel connection), the end (inside) is trimmed the length of the hex ridge removed. For the left (chamber connection), the end is trimmed the length of the trimmed slip bushing inside, which is itself trimmed to about half the socket depth of the tee.
The 3x1.5" bushing on the right is trimmed to about 1/3 of the tee socket depth. Care needs to be taken to buy a bushing that is of solid construction on the outside, and not ribbed like some, as when you trim these, you will be left with holes (bad). Then, the 3/4" bushing has it's hex removed and trimmed the length of the hex ridge. Both are solvent welded together, but DO NOT solvent weld them into the tee.
For connection into the tee, the bushing assembly is attached by about 8 1/4"-20 machine screws, spaced evenly and, for aesthetics, in one line, not crooked. Before drilling and tapping, assemble the rest of the valve. Then, when you're ready to seal the valve up, place on a hard flat surface with the chamber port down. Place the bushing on top of the service port sealing gasket (about 1/8" neoprene), and then set one or two 25 pound weights on top of it (depending on the hardness of the rubber gasket). While the gasket is depressed, drill and tap the holes for the screws, and then fasten the bushing assembly in place with the machine screws. You are now set.
I drew this drawing roughly to scale (but taking the measurements in hundredths of inches and dividing by four to get the number of pixels), but rounding and approximation were used heavily, so it is best to lift measurements from the parts you yourself order to build this valve. I intended this to be helpful for anybody wanted to build a Supah-valve imitation, and those interested in building chamber-sealing valves without special tooling. Good luck.
i for years thought a supah-valve was a barrel sealing valve 
Oh well i wonder what else ive been wrong about:roll:
