Pressure Washer

[bc_gold 87]

A recent addition 13 HP Honda, coupled to a General triplex gear driven pump. Apparently the gear driven pumps will draw water from a tank while all other types require positive inlet pressure.

 

My question is can you change the rotation of a left hand pump to right hand to use on the gear drive.

 

Edited February 25 by bc_gold

[Ed Kennell 38,659]

If it is as simple as this, yes.       Note the inlet and outlet are also reversed.

[Handy Don 12,460]

3 hours ago, bc_gold said:

A recent addition 13 HP Honda, coupled to a General triplex gear driven pump. Apparently the gear driven pumps will draw water from a tank while all other types require positive inlet pressure.

 

My question is can you change the rotation of a left hand pump to right hand to use on the gear drive.

 

That looks to me like a geared drive piston pump with three cylinders (judging from what look like the caps for three one-way valves along the right side of the image). There are likely three similar caps on the bottom. One set is inlet and one set is outlet. The pistons are typically at 120º spacing on the internal shaft to balance the output stream.

I don’t know if rotating the input shaft in the opposite directly will affect the piston movement or balance.

I don’t know if the inlet and outlet one-way valves and their seats in the manifold/header are interchangeable.

[bc_gold 87]

 

 

 

7 hours ago, Handy Don said:

That looks to me like a geared drive piston pump with three cylinders (judging from what look like the caps for three one-way valves along the right side of the image). There are likely three similar caps on the bottom. One set is inlet and one set is outlet. The pistons are typically at 120º spacing on the internal shaft to balance the output stream.

I don’t know if rotating the input shaft in the opposite directly will affect the piston movement or balance.

I don’t know if the inlet and outlet one-way valves and their seats in the manifold/header are interchangeable.

 

Somewhere I had read you can remove the head flip it 180 degrees so I assume this would reposition the valves no mention of changing the crankshaft.

 

The pump has been frozen not sure what if any internal damage has occurred, regardless the price was right.

 

The specs for the pump.

 

 

 

Edited February 26 by bc_gold

[Handy Don 12,460]

1 minute ago, bc_gold said:

 

Somewhere I had read you can remove the head flip it 180 degrees so I assume this would reposition the valves no mention of changing the crankshaft.

 

The pump has been frozen not sure what if any internal damage has occurred, regardless the price was right.

I just took a peek at some of the service manuals for this and I’m drawing on some personal experience...

 

The head does look like it might be symmetric around the center axis so I agree that it’s certainly worth a try at low pressure/volume assuming access to the inlet and outlet ports will still be ok! Note that this means NOT changing the pump rotation, right?

 

I got a sweet deal on a PW where the owner had left plain water in the pump over the winter and it had repeatedly frozen. I really only wanted the engine, but I took the pump apart to see if a set of valves would fix it. No joy--the inner wall holding the inlet valve seats had been distorted and without taking the time to look further, I was skeptical that running it under pressure would be safe. After $8 for the brass body and parts from the pump as scrap I had a nice 7.5hp OHC B&S engine with the frame/wheels/handle/hose/wand for $42. Then found a great pump off a PW with a blown engine for $25. Oh, and I always prime the pump with RV antifreeze every Fall!

[bc_gold 87]

6 hours ago, Handy Don said:

I just took a peek at some of the service manuals for this and I’m drawing on some personal experience...

 

The head does look like it might be symmetric around the center axis so I agree that it’s certainly worth a try at low pressure/volume assuming access to the inlet and outlet ports will still be ok! Note that this means NOT changing the pump rotation, right?

 

I got a sweet deal on a PW where the owner had left plain water in the pump over the winter and it had repeatedly frozen. I really only wanted the engine, but I took the pump apart to see if a set of valves would fix it. No joy--the inner wall holding the inlet valve seats had been distorted and without taking the time to look further, I was skeptical that running it under pressure would be safe. After $8 for the brass body and parts from the pump as scrap I had a nice 7.5hp OHC B&S engine with the frame/wheels/handle/hose/wand for $42. Then found a great pump off a PW with a blown engine for $25. Oh, and I always prime the pump with RV antifreeze every Fall!

 

By flipping the head the bottom 180 the bottom valves would now be top side also the water inlet reversed this I believe would require a change of crankshaft rotation to make pressure at the nozzle.

 

Ceramic pistons valves connecting rods and o-rings needed to rebuild this pump is available via eBay for about $300.00 Canadian. Triplex pressure pumps are of commercial quality the gear drive takes the stress off of the engine and extends the lifespan of the pump by running it at a leisurely 1450 RPM.

[bc_gold 87]

The pump below also manufactured by General, looks like flipping the head 180 degrees won't work. These pumps are designed for belt and gear drives.

 

Edited February 26 by bc_gold

[Handy Don 12,460]

12 hours ago, bc_gold said:

By flipping the head the bottom 180 the bottom valves would now be top side also the water inlet reversed this I believe would require a change of crankshaft rotation to make pressure at the nozzle.

Unlike internal combustion engines with timed valve lifters, these pumps use spring loaded valves actuated by pressure.

When pressure is “negative”, i.e. the piston is pulling away from the head, the inlet valve will open and the outlet valve will shut.

When pressure is “positive”, i.e. the piston is pushing toward the head, the inlet valve will shut and the outlet valve will open.

This is regardless of which way the head is flipped since the valves themselves are fully contained in the head. Flipping will only reposition the inlet and outlet ports.

 

Changing the pump rotation direction does not alter the basic up/down motion of the piston so it does not affect the operation of the valves. It MIGHT affect how the crankshaft and connecting rods are designed to work since the crank will be 180º of rotation off--compressing where it was previously “intaking” and vice versa. Reversed rotation may also affect how internal lubrication pumping operates.

 

Edited February 26 by Handy Don