Old belt driven fresh water pump

superheat6k

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The fresh water pump on my 1986 Fairline is a plunger diaphragm pump with a belt drive.

The diaphragm is leaking, I am trying to size a modern replacement - any ideas on what capacity I should look for. Typical flow rates seem to be 7, 12 & 17 litres/ min.

Boat is 36' with 2 heads / showers (only 1 in use at once), plus galley hot and cold. The calorifier relief valve is 3.5 Bar.

I also need to connect to the Fairline brown plastic water pipe work, which uses threaded connectors using an O ring and plastic backup ring. Not sure how to connect these to modern fittings yet.

I have noticed the Chinese Seaflo range offer what looks like a reasonable pump for about 1/2 the price an equivalent Jabsco Par Max - any good / bad experiences ?
 
It's probably a Jabsco pump. You can still get replacement diaphragms for some of these from the Jabsco Shop.

Thanks. However, it makes the system pulse even with an accumulator, its output isn't too great and it is quite noisy, so I would rather install something a bit newer.
 
Isn't the pipework speedfit or hep2o type ?fittings are interchangeable, best to use inserts but need to check these for compatibility.
 
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I have the same type of pump as you are thinking of replacing, mine developed a fault so I replaced it with a Johnson diaphragm type, my opinion is that it does not perform as well as the old Jabsco belt driven one, regarding noise, it is just different not quieter.
 
Installed the new Seaflo 41 model pump today. The power and flow is a lot more than the old Par plunger pump.

It initially lifted the calorifier relief, but has an adjuster to set the desired cut off pressure. Definitely quieter.

However, its peak load is tripping the breaker switch on the panel, so will be fitting a 30a relay, and from the thread here on excessive induced EMF I might also fit a bypass diode.

If anyone would like the old plunger pump as a freebie for spares or repair please PM me. The diaphragm was a bit leaky, but nothing too severe.
 
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