Do I need low pressure bath shower mixer and taps for my boat?

[narrowboatmick]

Hi , does anybody know wether I need low pressure taps and bath shower mixer for my narrowboat.I have a Jabasco water pressure pump.Info on the side of the pump is 2.9 gallons per minute and 4.7 amps @0.7 bar.I did nt think about this issue until I started looking for taps and bath shower mixers and some claim to be for high or low pressure water flow, I guess my instinct is to go with low pressure fittings but I may be wrong.The bath shower mixer is 30 feet from the pump.Also, rather than take the water pipe under the bathroom floor from the sink to the bathshower fitting and risk it freezing in winter I want to take it up over the doorframe,but would this extra height reduce the water pressure? thanks, Mick.

[RLWP]

The pipe won't freeze under the floor because the canal water is always above freezing point. It wouldn't be a liquid otherwise, would it? However, my preference is to put the pipes where I can get to the easily, so under the floor is out for me.

 

I'd guess low pressure too

 

Richard

[narrowboatmick]

The pipe won't freeze under the floor because the canal water is always above freezing point. It wouldn't be a liquid otherwise, would it? However, my preference is to put the pipes where I can get to the easily, so under the floor is out for me.

 

I'd guess low pressure too

 

Richard

I suppos it would be easier to get to if not under the floor,I raised the point about freezing because in the winnter just gone All things the bottles of water and milk froze when I left the boat for a couple of days, thanks for your reply Richard.

[alan_fincher]

I suppos it would be easier to get to if not under the floor,I raised the point about freezing because in the winnter just gone All things the bottles of water and milk froze when I left the boat for a couple of days, thanks for your reply Richard.

If you are leaving the boat unheated on days when it is freezing outside, your suggestion of a pipe running over a doorway is probably more likely to freeze than one routed under floors, IMO.

[RLWP]

If you are leaving the boat unheated on days when it is freezing outside, your suggestion of a pipe running over a doorway is probably more likely to freeze than one routed under floors, IMO.

 

I'd go with that. The joints we had freeze and burst last winter were all at gunnel height

 

Richard

[ditchcrawler]

I'd go with that. The joints we had freeze and burst last winter were all at gunnel height

 

Richard

The only one I had go, was 250 mm above the floor but that was the only one with water trapped in it. I am not to sure about those pump ratings, I think most are about 3 bar which is probably greater than the mains pressure in our house

[ChrisPy]

the level of the intermediate pipe has absolutely no impact on the pressure.

the level of the shower outlet does affect the pressure. which is why on a very low pressure system you get less flow if you lift the shower outlet to head height.

the fittings should include an instruction sheet stating the working pressure limits.

if your pump delivers 0.7bar at floor level, you will see about 0.5bar at head height, and 0.6bar at the shower mixer.

but the pump cutout is probably higher than 0.7bar.

Edited July 22, 2010 by ChrisPy

[Robbo]

Hi , does anybody know wether I need low pressure taps and bath shower mixer for my narrowboat.I have a Jabasco water pressure pump.Info on the side of the pump is 2.9 gallons per minute and 4.7 amps @0.7 bar.I did nt think about this issue until I started looking for taps and bath shower mixers and some claim to be for high or low pressure water flow, I guess my instinct is to go with low pressure fittings but I may be wrong.The bath shower mixer is 30 feet from the pump.Also, rather than take the water pipe under the bathroom floor from the sink to the bathshower fitting and risk it freezing in winter I want to take it up over the doorframe,but would this extra height reduce the water pressure? thanks, Mick.

 

I would take the pipe as low as you can due to if it does leak it will keep damage to a minimum.

 

Also check the shower's flow rate. Distance, pipe size and bends in the pipe will effect the flow to/from the pump.

[PhilR]

Mick

 

I'm not sure about the technical issues, although I guess you need a low pressure mixer. Here are details of my own freshwater system (on a 30 year old boat) which might reassure you on a few points:

 

The Shureflo pump and accumulater are next to the water tank under the bow well deck. All pipework is Polyplumb type 15mm (apart from chromed copper above the shower mixer). None of the pipework is below the floor. There is H & C supply to a sink, wash basin and shower. The shower is furthest from the pump and on the port side of the boat. Every thing else is on the starboard side. The total pipe run from pump to shower is approx 40 feet. The hot and cold pipework to the shower mixer pass across the boat above the roof lining, but under the insulation.

This is obviously an old and low tech system, but it works great and friends always comment on how powerful the shower is.

 

Regarding frost damage, I was caught out once by an autumn/early winter frost (unforecast!!) with a temperature of -15C. 0n that occasion a chromed copper pipe popped out of the compression joints and was lying in the shower tray bent like a boomerang. Surprisingly, the Morco water heater was undamaged.

 

Personally, I would have no concern about hidden pipe runs in Polyplum (or similar) provided that all compression joints are visible and easily accessible.

 

HTH

 

Phil

[narrowboatmick]

the level of the intermediate pipe has absolutely no impact on the pressure.

the level of the shower outlet does affect the pressure. which is why on a very low pressure system you get less flow if you lift the shower outlet to head height.

the fittings should include an instruction sheet stating the working pressure limits.

if your pump delivers 0.7bar at floor level, you will see about 0.5bar at head height, and 0.6bar at the shower mixer.

but the pump cutout is probably higher than 0.7bar.

Thanks for that, I havent bought the fittings yet but I will try and get the working pressure limits before I do, mick.

 

I would take the pipe as low as you can due to if it does leak it will keep damage to a minimum.

 

Also check the shower's flow rate. Distance, pipe size and bends in the pipe will effect the flow to/from the pump.

Thanks ,i ll do that,mick

 

 

Mick

 

I'm not sure about the technical issues, although I guess you need a low pressure mixer. Here are details of my own freshwater system (on a 30 year old boat) which might reassure you on a few points:

 

The Shureflo pump and accumulater are next to the water tank under the bow well deck. All pipework is Polyplumb type 15mm (apart from chromed copper above the shower mixer). None of the pipework is below the floor. There is H & C supply to a sink, wash basin and shower. The shower is furthest from the pump and on the port side of the boat. Every thing else is on the starboard side. The total pipe run from pump to shower is approx 40 feet. The hot and cold pipework to the shower mixer pass across the boat above the roof lining, but under the insulation.

This is obviously an old and low tech system, but it works great and friends always comment on how powerful the shower is.

 

Regarding frost damage, I was caught out once by an autumn/early winter frost (unforecast!!) with a temperature of -15C. 0n that occasion a chromed copper pipe popped out of the compression joints and was lying in the shower tray bent like a boomerang. Surprisingly, the Morco water heater was undamaged.

 

Personally, I would have no concern about hidden pipe runs in Polyplum (or similar) provided that all compression joints are visible and easily accessible.

 

HTH

 

Phil

Thanks phil, thats similar to my set up apart from no accumilator as the wording on the pump box said I did nt need one,which probly raises another question, but i wil try trial and error with that one,yep I have the same 15 mm piping ,I will now feed it above the door frame and purchase the fitting in the next few days,running water for the first time in 7 month,phew will I be glad,mick.

[the grinch]

HIGH PRESSURE!

 

low pressure fittings are for gravity feed house systems, any system having a pump or pressure over 0.5 bar will make low pressure valves leak. (it blows the washers out)

[dunrhyl]

the level of the shower outlet does affect the pressure. which is why on a very low pressure system you get less flow if you lift the shower outlet to head height.

[narrowboatmick]

HIGH PRESSURE!

 

low pressure fittings are for gravity feed house systems, any system having a pump or pressure over 0.5 bar will make low pressure valves leak. (it blows the washers out)

Thanks for that , I think the best thing for me is to check the pressure details on the taps I buy and match them up to the pressure on the pump.

[ChrisPy]

Thanks for that , I think the best thing for me is to check the pressure details on the taps I buy and match them up to the pressure on the pump.

but remember the pump may be good for 2 bar.

[Robbo]

Thanks for that , I think the best thing for me is to check the pressure details on the taps I buy and match them up to the pressure on the pump.

 

http://www.tapcentre.com/faq/ - Water Pressure at the bottom, basically you need high pressure taps / shower.

 

For showers, take notice of the minimum flow rate, although you can always add another pump to your system.

[narrowboatmick]

http://www.tapcentre.com/faq/ - Water Pressure at the bottom, basically you need high pressure taps / shower.

 

For showers, take notice of the minimum flow rate, although you can always add another pump to your system.

Thanks for the link,it has some good info.

[jessie]

I know this is an old topic but Mick, what did you fit in the end and was it satisfactory?

 

I'm just about to fit a shower and have had advice both ways, high and low pressure, so would be interested to hear your results if you are still on the forum :-)

[frangar]

I had this problem too so I asked the manufacturer! Aqualisa came back saying I should use low pressure ones to give the best flow rate. As they make both types i just gave them the pump cut in/out pressure & flow rate. Have had the shower mixer fitted for 6 months with no problems. Some manufacturers say their units can be used with low or high pressure.

 

Hope that helps

 

Gareth

[Tony Brooks]

May I point out that the modern fad for 10mm or smaller feed pipes on modern taps may well cause the pump to cycle. I would fit 15mm or larger taps & shower outlets. the pump may still cycle but at a lower rate.

[jessie]

Thanks Gareth, that is useful to know. I fited the pump ages ago and can't remember the spec so i'll probably go for one that claims to be suitable for either.

 

Interesting point Tony, i'll stick to 15mm, thanks.

[ditchcrawler]

Thanks for that , I think the best thing for me is to check the pressure details on the taps I buy and match them up to the pressure on the pump.

Its the pump cutout pressure that you are looking for, it could well be anywhere between 2 and 3 Bar.

[Hawkmoth]

I would like to add to all the info imparted here that I've just replaced my old pump, which was rated at 2.9 gal/min for one giving 3.5 gal/min. The real gain was that the shower now works wonderfully.

It did work before, but was a bit weak. It's a standard B&Q temperature controlled mixer.

Bob