Hi all,
We are having problems maintaining the water level on our 1923 Stanley 740, have any of you got any suggestions? We've had the water pumps off and they're probably come off again. What size balls and what should their lift be with the half-shaft driven, long slow stroke pumps? We've recently reboilered the car and the pre-heater, clack/ check valve going in to the boiler and the dip tube are new. There's also a water pump pressure gauge, what pressure should it read in comparison to the boiler pressure? Thanks. George Hounslow.

George
Hear are the rules I follow when building pumps.

1. The optimum diameter for the bore that the ball seats on, is 0.707 x OD of ball. (COS 45) This will ensure that the contact angle is 45°. Flat top to the hole then seat the ball.

2. Lift should be restricted to no more then 1/6 th ball diameter

3. The minimum diameter of the bore that the ball moves in, is 1.31 x OD of ball. This will only just give enough clearance for the liquid to flow past the ball.

On the condensing cars, the Stanley text that I have referred to in the past has recommended 0.050" lift or clearance for the water power pump balls. I have adjustable ball checks on my 1916 Stanley Mt. Wagon and I have found that running a little closer clearance (0.040") will be quiter and still pump as much water for me.There are many, many tips to get better performance out of your water pumps. Most of it is just plain old mantenance. My biggest downfall has been plugged filters or even a filter screen that had too fine of a mesh for water to quickly pass. On the condensing cars there is a filter attached to the water tank's drain plug that occasionally needs cleaning. Greasy water pump check balls will also reduce the water flow. A spot of kerosene in the water tank will help that problem. TSP also will help reduce the problems. Are you using the correct water pump packing and is the slack in the stuffing boxexs properly taken up? Is your tank water getting too hot to be pumped? The list is endless.



Edited 1 times. Last edit at 07/02/12 07:57AM by SSsssteamer.

Thanks to both of you, I'll take your information on board. SSsssteamer, we are using the same packing as used in the steam taps in the pumps, although there is some old stuff still in there. We have taken the slack on the stuffing boxes up until there is only a slight drip from the pump. The water tank cannot be getting to hot as the car does not reuse the condensate, it just go through the condenser and out the back of the car. George.

Hi George,

The pumps in my 735 (the same as your pumps I guess) are fitted with 1/2" diameter balls. When I got the car they were badly pitted so I replaced them with stainless 304. Although they seem to be wearing faster than the steel originals, they seat down well; and I'm happy to replace them again if they wear out. It's possible that the balls in your pumps are also badly pitted and have damaged the seats - very little leakage soon makes the pump useless at 500+ psi. The balls should, and must be be fitted with brass 'tails' which slide in the guide hole in the check valve cap.

I ended up making a seat cutter in silver steel which re-cut the seats before I fitted the stainless balls.

The lift on my pump checks is now a shade under 0.040" for the delivery checks, and about 0.050" for the inlet checks - you can measure this by the following method:
1. Measure the 'length' of the ball to the little flat by the tail (easy with verniers)
2. Put a little ring of plasticine around the base of the 'tail' of the check ball
3. Reassembe it on the pump, CAREFULLY dismantle and CAREFULLY measure again.

The difference is your ball lift (it's a bit of a nobby method but it's good enough for this kind of thing!).

As SSsssteamer says, there is a removable filter cage just inside the big drain plug of the water tank - check that it's clear, these pumps are easily compromised by having any sort of restriction in their intake lines. Hint - I've got into the habit of periodically dropping the drain plug when blowing down and using the blowdown steam to clean the cage filter really well, before putting it back in ready for the next outing. I also do the fiter cage for the water auto at the same time.

I don't have a pressure gauge on the delivery side of either of my cars, so I can't comment on the delivery line pressure, suffice to say that it has to be respectably above boiler pressure, but if it's at say double, then you've probably got an unhealthy restriction in the delivery pipework. Dip tubes maybe! The reading that you get will also be affected by it's position in the system, and if you have an economiser or pre-heater.

Good luck!

Mark

George,

Regarding the pressure gauge between your pumps and boiler clack, as you know I have one of these fitted to our 10hp Stanley – often called a “Nelson gauge”. To absorb the “bounce” I use a glycerine filled gauge, Les Nelson uses a damper.

The pressure reading on the gauge should never be more than a few pounds above your boiler pressure, if it is you have got a restriction!

If you pump up your boiler using the hand pump to working pressure, when you have stopped pumping, the pressure on the “Nelson gauge” should stay the same as your boiler gauge. If it gradually goes down, your pump clacks could be passing, or as I found out, your bypass tap could be passing. I had to make a new one as the old one was well pitted and would not seat correctly.


Mark,

I haven’t heard of the balls being fitted with tails before, I can see the advantage of keeping the ball inline with the seat, but is this common practice?

Don

you use a snubber between the gauge and the pump.
Rolly

Thanks all, we fitted some washers under the clack cap and it now pumps better (so far!). George.

To answer Don's question - I don't know! Both of my condensing cars are equipped with the geared down pumps driven from the right hand (UK offide) rear axle, and they both had plain steel balls with brass tails attached; only about 1/8" diameter and 3/4" long. The tail has three flats filed along it's length to allow water to move freely into the blind hole that it sits in, in the valve cap. I assume that all the condensing cars are equipped thus.

On my 740, the valve seats were so badly worn (and I think re-cut at some time), that I moved away from the balls completely and made up some specially shaped bronze valves which have an 'O' ring embedded in their seating face, similar to something David Nergaard did some years ago. I have to say it's been very sucessful so far (1400 miles), totally quiet and still seal at very low speed. I carry a few spare 'O' rings just in case :-)

Well done, George for getting your pumps to perform, that's another step closer to success!
Cheers,

Mark

Hi Mark,
Took the car for MOT today, clack into pre-heater leaking so couldn't get any water into boiler, lucky that the MOT centre was so close! We'll have to reseat it tommorrow and fit new balls. George