1 Steam Cars : Phorum
General Steam Car topics
Pulsation dampeners
Posted by: Peter Heid (IP Logged)
Date: July 08, 2003 07:22PM
<HTML>I thought I would take this out of the drip catagory so it might be found under it's own topic. Having worked on pressure washers for many years, I have had a bit of experience with these devices. The max pressure listed on the unit is that of the system, not the peak, pulse pressure. The Giant brand, model 22050 is a nickel plated unit with a 3/8 port and rated to 12 gpm at 2500 psi max at 200 degrees F.. It comes pre charged with 600 psi and is about 55 bux from Dultmeier sales <dultmeier.com> or 1-800-553-6975. They sell many other units also but the Giant seems to be the best value. About the pre charge, this should be set to 1/2 the working pressure but no more than 1/2 the max pressure and it should be charged with nitrogen. A competent motorcycle or snowmobile shop will often rebuild shocks and have the capability to precharge to and pressure needed.
Another thought on this subject, pulsation dampeners can be in the form of a special hose. A hose suitable for 1500 psi and 5 gpm is about 10 bux and is 40 inches in length from the same place. They can be run in parallel for increased flow rates. These would seem well suited to many applications including older vehicles.
Peter Heid</HTML>
Another thought on this subject, pulsation dampeners can be in the form of a special hose. A hose suitable for 1500 psi and 5 gpm is about 10 bux and is 40 inches in length from the same place. They can be run in parallel for increased flow rates. These would seem well suited to many applications including older vehicles.
Peter Heid</HTML>
Re: Pulsation dampeners
Posted by: Roland Evans (IP Logged)
Date: July 08, 2003 08:34PM
<HTML>On a Stanley water system or for that mater any reciprocating pump you can eliminate almost the entire hammer by going to a larger pipe and larger check valves between the pump and the boiler. Use a pipe one or two sizes larger then the piston of the pump. I couldn’t believe the small 5/16 copper tube and checks used on my Stanley.
On my boats I use ½ and ¾ IPS pipe and checks two sizes larger then the pipe. I can hardly hear any sound.
I haven’t re-piped the Stanley, as I like to know and hear the sound of the feed water.
Rolly</HTML>
On my boats I use ½ and ¾ IPS pipe and checks two sizes larger then the pipe. I can hardly hear any sound.
I haven’t re-piped the Stanley, as I like to know and hear the sound of the feed water.
Rolly</HTML>
Re: Pulsation dampeners
Posted by: Peter Heid (IP Logged)
Date: July 08, 2003 11:32PM
<HTML>Rolly,
Your correct but some instances won't allow the use of pipes that large or there use is cost prohibitive. Pressure washers usually have a monotube coil with a smaller inside diameter than the bore of the pump. When the pipe is the same diameter as the cylinder, the water will have a velocity in the pipe equal to the velocity in the pump. Of course if you double the diameter of the pipe, the velocity will be 1/4. Another method if building from scratch is to use enough cylinders so the pulses are smoothed out.
Peter Heid</HTML>
Your correct but some instances won't allow the use of pipes that large or there use is cost prohibitive. Pressure washers usually have a monotube coil with a smaller inside diameter than the bore of the pump. When the pipe is the same diameter as the cylinder, the water will have a velocity in the pipe equal to the velocity in the pump. Of course if you double the diameter of the pipe, the velocity will be 1/4. Another method if building from scratch is to use enough cylinders so the pulses are smoothed out.
Peter Heid</HTML>
Re: Pulsation dampeners
Posted by: Rolly (IP Logged)
Date: July 09, 2003 08:46AM
<HTML>Another problem with a lot of pumps on the market is that they are short stroke high speed.
You should use long stroke slow speed pumps. Double acting or three cylinder pumps.
Rolly</HTML>
You should use long stroke slow speed pumps. Double acting or three cylinder pumps.
Rolly</HTML>
Re: Pulsation dampeners
Posted by: Peter Brow (IP Logged)
Date: July 09, 2003 10:19AM
<HTML>Hi Peter and Rolly,
Thanks for the info and sources. Pipe a size or two larger than the plunger bores would be easy to fit, though I like the idea of flexible hose for a secret reason which bears on possible patent considerations. However, most of the hi-pressure hose I have seen is pretty small in diameter, so it would take several to equal a 3/4" ID flowpath.
My feed pump design is a bit odd. 3/4" bore plunger, double-headed, with 1" stroke. Lots of excess capacity; no running dry on hills for me. Plunger speed is 1/4 engine piston speed, but at the same cyclic rate as the pumps are crosshead-driven. So it is a low-speed, short-stroke pump. The fluid velocities are below limits given by Kent. Poppet check valve flowpaths have the same cross-section at full lift as the plungers -- a no-restriction design. No restriction design required poppet rather than ball valves due to the plunger diameter. I guess the design isn't so Stanley-like after all.
Original plan for plumbing was feedwater line of the same ID as pump plungers (3/4").
$55 for a pulsation damper, that's a cheap and simple solution. Thanks Peter. Then again, do you know of any 3/4" or 1" ID flex hose that can handle 200°F/500 psi working conditions? Microscopic expansion/contraction over several feet length could take out all the pulses with no N2 or gizmos needed. Seems like nearly everything in this design is ending up flexible. Earl's Supply just popped into my head, but I haven't had one of their catalogs in years. I'll see what they have. Dig their wild-colored braided lines & hitech fittings -- pretty trick stuff for a steam car!
On third thought, Rolly, I might end up wanting to hear those pumps working. :)
Peter B.</HTML>
Thanks for the info and sources. Pipe a size or two larger than the plunger bores would be easy to fit, though I like the idea of flexible hose for a secret reason which bears on possible patent considerations. However, most of the hi-pressure hose I have seen is pretty small in diameter, so it would take several to equal a 3/4" ID flowpath.
My feed pump design is a bit odd. 3/4" bore plunger, double-headed, with 1" stroke. Lots of excess capacity; no running dry on hills for me. Plunger speed is 1/4 engine piston speed, but at the same cyclic rate as the pumps are crosshead-driven. So it is a low-speed, short-stroke pump. The fluid velocities are below limits given by Kent. Poppet check valve flowpaths have the same cross-section at full lift as the plungers -- a no-restriction design. No restriction design required poppet rather than ball valves due to the plunger diameter. I guess the design isn't so Stanley-like after all.
Original plan for plumbing was feedwater line of the same ID as pump plungers (3/4").
$55 for a pulsation damper, that's a cheap and simple solution. Thanks Peter. Then again, do you know of any 3/4" or 1" ID flex hose that can handle 200°F/500 psi working conditions? Microscopic expansion/contraction over several feet length could take out all the pulses with no N2 or gizmos needed. Seems like nearly everything in this design is ending up flexible. Earl's Supply just popped into my head, but I haven't had one of their catalogs in years. I'll see what they have. Dig their wild-colored braided lines & hitech fittings -- pretty trick stuff for a steam car!
On third thought, Rolly, I might end up wanting to hear those pumps working. :)
Peter B.</HTML>
Re: Pulsation dampeners
Posted by: SSsssteamer (IP Logged)
Date: July 09, 2003 07:56PM
<HTML>Having seen so many Stanley boiler scortched from a broken feedwater line that went unnoticed, I made an update for reliability. In our noncondensing Stanley's, feed water line between the pumps and the boiler, I use a high pressure wire armored hydraulic line. The flexible line takes the shock that continually breaks the Stanley's 5/16" copper feedwater line. The flex line will not take the high heat from the boiler so the last two feet to the boiler I have it plumbed with 1/4" pipe. No more feedwater line problems for me. I also perfer to hear the click of the boiler check valves. When they quite clicking, I know that my water tank has finally gone dry and my driving range has suddenly became very limited.</HTML>
Re: Pulsation dampeners
Posted by: George Nutz (IP Logged)
Date: July 09, 2003 11:33PM
<HTML> Buck Boudeman uses a stainless flexible corrugated? line for his high pressure steam line to the engine, it is very strong and can take a lot of shock and movement. I would think a smaller version would work very well in the feedwater line and reduce pulsations. Coburn's Vanderbilt has one on the steam line to the engine., very flexible and forgiving. Cost??
George</HTML>
George</HTML>
Re: Pulsation dampeners
Posted by: Peter Brow (IP Logged)
Date: July 10, 2003 07:20AM
<HTML>Pat and George,
Thanks for the info. It is good to hear that high-pressure braided flex hose & corrugated flex pipe are used successfully on steam cars already. The steel pipes & U-bends used for old time steam lines were supposed to flex plenty thanks to their length, but a corrugated hi-psi pipe should do better without the alarming steam line breaks occasionally mentioned in the steam literature.
As for flex hose with pulse damper, vs flex hose without a pulse damper, I am not sure. This is going to need some experiments once the pumps are finished. Pump thru a flex hose and discharge valve I guess, at simulated max rate/pressure, and see if the pressure gauge needle jumps around like crazy or if anything hammers. If not, forget the pressure damper; if so, time to make some phone calls. Need to get a small gas engine & make up pulley drive/crank rig to run pump for those tests.
Peter B.</HTML>
Thanks for the info. It is good to hear that high-pressure braided flex hose & corrugated flex pipe are used successfully on steam cars already. The steel pipes & U-bends used for old time steam lines were supposed to flex plenty thanks to their length, but a corrugated hi-psi pipe should do better without the alarming steam line breaks occasionally mentioned in the steam literature.
As for flex hose with pulse damper, vs flex hose without a pulse damper, I am not sure. This is going to need some experiments once the pumps are finished. Pump thru a flex hose and discharge valve I guess, at simulated max rate/pressure, and see if the pressure gauge needle jumps around like crazy or if anything hammers. If not, forget the pressure damper; if so, time to make some phone calls. Need to get a small gas engine & make up pulley drive/crank rig to run pump for those tests.
Peter B.</HTML>
Re: Pulsation dampeners
Posted by: C Benson (IP Logged)
Date: July 10, 2003 09:10AM
<HTML>But I'm not sure that corrugated line may store cyl oil when I dont want it to,,,Ben</HTML>
Re: Pulsation dampeners
Posted by: Mike Clark (IP Logged)
Date: July 10, 2003 08:16PM
<HTML>Corrugated flex pipe is working well for me on my main steam line. I have about 18 inches straight plain SS pipe from the superheater then the same length of Swagelok brand flex pipe into the valve chest. It takes the steam round a 90 degree bend on about a 6 inch radius. There is no U bend on the pipe and I got rid of two elbows and a Stanley type flexible fitting.
At last the car stays clean underneath with no oil or steam leaks. Swagelok can supply flex pipe with standard size male or female pipe threaded ends and for ease of assembly I used a Swagelok compression fitting at the front end which locks onto a Swagelok stub welded into my plain steam pipe. Minimum bore size used 1/2 inch.
Haven't noticed any problem with oil collecting in the corrugations.
It was horribly expensive!!! But worth it for the result.
Mike</HTML>
At last the car stays clean underneath with no oil or steam leaks. Swagelok can supply flex pipe with standard size male or female pipe threaded ends and for ease of assembly I used a Swagelok compression fitting at the front end which locks onto a Swagelok stub welded into my plain steam pipe. Minimum bore size used 1/2 inch.
Haven't noticed any problem with oil collecting in the corrugations.
It was horribly expensive!!! But worth it for the result.
Mike</HTML>
Re: Pulsation dampeners
Posted by: chuk williams (IP Logged)
Date: July 11, 2003 03:47AM
<HTML>Gentlemen;
On my car, I'm using the s/s flex line for the last bit
into the manifold-and it's worked well for the past two
years with no problems.....I think the cost was $32 for
a 1 foot long-1/2 inch NPT unit. The feedpump noise
problem was cured with the addition of a 2 foot long
piece of the flex hose-especially made for the purpose
and sold by Surplus Center for $6---it's been doing a
good job for the past 2 years also......
Cheers---Chuk</HTML>
On my car, I'm using the s/s flex line for the last bit
into the manifold-and it's worked well for the past two
years with no problems.....I think the cost was $32 for
a 1 foot long-1/2 inch NPT unit. The feedpump noise
problem was cured with the addition of a 2 foot long
piece of the flex hose-especially made for the purpose
and sold by Surplus Center for $6---it's been doing a
good job for the past 2 years also......
Cheers---Chuk</HTML>
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