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turfmanagementspecialty
10-09-2010, 11:39 AM
I just replaced the diaphragms in my Hypro D403 pump and went out to spray today and the pressure was pulsating a bit. Pressure would go up to 160 then drop to just over 100. What could possibly be the issue? Thanks

jbturf
10-09-2010, 09:29 PM
i recently had a pulsing issue on my 403, up down up down
pretty fast though, it would make the hose jerk around

turned out to be a tiny piece of crud keeping one of the
valves stuck open

luckily for me it was only the 2nd valve i checked till
i found the culprit, (there are 6 of them)

g/l

ToniDavies
10-13-2010, 10:57 AM
Sounds like you do not have enough air pressure in the head of the pump. You want to add about 40 psi air pressure start up the system is the gauge is bouncing all over the place (pulsing) slowing let some air out until it is steady.

jbturf
10-13-2010, 09:19 PM
Sounds like you do not have enough air pressure in the head of the pump. You want to add about 40 psi air pressure start up the system is the gauge is bouncing all over the place (pulsing) slowing let some air out until it is steady.


how do you add air to the d403?

ToniDavies
10-14-2010, 10:21 AM
Sorry JBTurf the D403 does not have an air valve. I am so used to the question with the D252, D30 etc and forgot this model Hypro pump does not have an air valve.

Ric
10-14-2010, 11:07 AM
Air is more compressable than water. Adding a Water Hammer damper is fairly simple but only masks a problem on certain style pumps. They are nothing more than a Tee on the pressure line side that goes to a dead end air chamber. They are installed so gravity keeps the solution out by compressing the air which is higher. On pressure washers they use a special hose that expands as a pulse damper

Pumptecguy
10-14-2010, 01:27 PM
Air is more compressable than water. Adding a Water Hammer damper is fairly simple but only masks a problem on certain style pumps. They are nothing more than a Tee on the pressure line side that goes to a dead end air chamber. They are installed so gravity keeps the solution out by compressing the air which is higher. On pressure washers they use a special hose that expands as a pulse damper

The pulsation from the pump can come from a few places. Air leaks on the inlet side, a crack on the pump body, an old regulator valve that leaks internally and has become hydraulically unstable, etc....

You are correct that air will compress and water really will not. Accumulators (dampeners) are specially designed and precharged/loaded based upon the system pressure and displacement. A simple Tee with a vessel of air above only works in cartoons or your imagination. The water will force the air into solution even at very low pressure and remove any imagined dampening. Many, many people have been harmed by this misunderstanding when their galvanized plumbing vessel exploded on their high pressure washer. They usually do not live to tell. It is not a joke.

Pulse (dampening) hose is specially wound to absorb energy (pulse). There is only 1 quality manufacturer and the rest is junk. It was originally developed by an engineer at Chrysler to eliminate the chirping sound in early power steering systems. Pumptec is largest customer of pulse hose in the country and one of the founders refined it for pressure washer use 35 years ago.

Ric
10-14-2010, 07:36 PM
The pulsation from the pump can come from a few places. Air leaks on the inlet side, a crack on the pump body, an old regulator valve that leaks internally and has become hydraulically unstable, etc....

You are correct that air will compress and water really will not. Accumulators (dampeners) are specially designed and precharged/loaded based upon the system pressure and displacement. A simple Tee with a vessel of air above only works in cartoons or your imagination. The water will force the air into solution even at very low pressure and remove any imagined dampening. Many, many people have been harmed by this misunderstanding when their galvanized plumbing vessel exploded on their high pressure washer. They usually do not live to tell. It is not a joke.

Pulse (dampening) hose is specially wound to absorb energy (pulse). There is only 1 quality manufacturer and the rest is junk. It was originally developed by an engineer at Chrysler to eliminate the chirping sound in early power steering systems. Pumptec is largest customer of pulse hose in the country and one of the founders refined it for pressure washer use 35 years ago.

Pump Guy

Sorry BUT, Tell that to my Beam Pump and my galvanized Air Chamber that has been working for well over 10 years. The trick is to have a long small diameter pipe leading to a large diameter pipe as a chamber. The Higher the Chamber above the tee the better. When the pump is off you must relief pressure from the hose or out let side.

Pumptecguy
10-17-2010, 09:18 AM
Pump Guy

Sorry BUT, Tell that to my Beam Pump and my galvanized Air Chamber that has been working for well over 10 years. The trick is to have a long small diameter pipe leading to a large diameter pipe as a chamber. The Higher the Chamber above the tee the better. When the pump is off you must relief pressure from the hose or out let side.

No need to apologize. Maybe you need a visual example:
Take a clear bowl line strainer and attach it above any diameter pipe you pick, then start to pressurize. If your eyes are open, then you will see all the air evacuated and that clear bowl filled with water. Can you imagine anything magical about your galvanized version of this? All you have created is a small water tower that wil hold a volume of water, but it does not dampen.

This misconception is very dangerous. Your Bean is probably at a low enough pressure, but there are others that will use this at higher pressure with lower strength materials and get hurt.

There are old, cast iron accumulators that look like these ad hoc plumbing creations you reference, but these are made correctly with diaphragms and some type of precharge or load. Shade tree mechanics saw these devices and said, 'Ah, shoot....I can just make one of these. It's just plumbing fittings'.

Take it off and test your pump. It will preform the same, unless you want to imagine a change. Who knows, you may even look inside and see that long ago it used to have a bladder or ball inside to absorb energy.

Ric
10-17-2010, 10:07 AM
No need to apologize. Maybe you need a visual example:
Take a clear bowl line strainer and attach it above any diameter pipe you pick, then start to pressurize. If your eyes are open, then you will see all the air evacuated and that clear bowl filled with water. Can you imagine anything magical about your galvanized version of this? All you have created is a small water tower that wil hold a volume of water, but it does not dampen.

This misconception is very dangerous. Your Bean is probably at a low enough pressure, but there are others that will use this at higher pressure with lower strength materials and get hurt.

There are old, cast iron accumulators that look like these ad hoc plumbing creations you reference, but these are made correctly with diaphragms and some type of precharge or load. Shade tree mechanics saw these devices and said, 'Ah, shoot....I can just make one of these. It's just plumbing fittings'.

Take it off and test your pump. It will preform the same, unless you want to imagine a change. Who knows, you may even look inside and see that long ago it used to have a bladder or ball inside to absorb energy.

Pumpguy

Once again It has BEEN WORKING for over 10 years on my Beam pump and longer on other beam pumps since that was the way the factory installed them.

Pumptecguy
10-18-2010, 10:32 AM
Pumpguy

Once again It has BEEN WORKING for over 10 years on my Beam pump and longer on other beam pumps since that was the way the factory installed them.

I buried a St Christopher statue in my backyard and my house sold. It must have been the statue.

You can form your opinion about my action and conclusion, and I will do the same about yours.

We will leave it up to the rest of the group to decide and hope no one gets hurt.

robert@rittenhouse
10-18-2010, 10:46 AM
Is the Bean pump a piston pump?

The D403 is a diaphragm pump and I vote for bad regulator that is causing the fluctuating pressure.

Ric
10-18-2010, 11:07 AM
Is the Bean pump a piston pump?

The D403 is a diaphragm pump and I vote for bad regulator that is causing the fluctuating pressure.

Robert

Of course it is a very old Bean Piston Pump. I got it used and it was plumbed with a Galvanized pipe Air Chamber. If any pump is going to fluctuating pressure a single Piston is. Plus this pump is low RPM. The Air Chamber must work because I don't get any Pulsing

robert@rittenhouse
10-18-2010, 11:36 AM
Ya, higher volume Piston pumps have to have some sort of pulsation dampener or you get the "hammer" effect.

Also, the hose you were talking about is called a "Surge Hose" which essentially does the same thing.

The D403 is a completely different animal than your Bean piston pump. It really sounds like a failing regulator (a 9910-GR40) or less likely there is a problem on the suction side of the pump. Such as drawing air through a loose fitting, or missing o-ring on the filter. Or maybe something blocking the suction inside the hose or bottom of the tank.

A surge hose or pulsation dampener is not going to fix these problems.