water pipe

[John Orentas]

Colin.

 

Why all this 'pressure reducing valve' stuff. The Surefow pumps that most boats are fitted with have an adjustable pressure switch, it is an horrible contraption but it can be made to work and much improved if fitted with the alternative low pressure spring. I have also found that water systems function perfectly well at one bar (14 psi). The ratings on calorifier and other items are of course MAXIMUM pressures.

 

Much better to fit a good quality pressure switch and gauge as previous thread.

[Keeping Up]

If the calorifier is labelled for 20psi safe working pressure it would be unwise to ignore this. To get over this problem you will need to fit a pressure reducing valve and a pressure gauge. The pressure gauge needs to be fitted after the pressure reducing valve which is manually adjustable. The gauge will allow you to see the pressure going into the calorifier as you set the valve, in setting the valve start at the lowest pressure possible and adjust the valve up to 20 psi. You will need to buy a valve that is adjustable down to a minimum of 1 bar/14psi. You can do this using a gate valve instead of a pressure reducing valve but it will require the gate valve to be locked off to avoid anyone accidentally opening it and over-pressuring the calorifier. You could remove the handle of the gate valve after setting, I personally would go for the pressure reducing valve.

This is assuming that your water pump is delivering over 20psi even if the pump is opperating at around this pressure you need to safegaurd the calorifier for any quirks with the pump. You can set the pump to cut out at 20psi but this will leave a short band for the pump to opperate in and this is also assuming that the pump has an adjustable pressure switch. Considering the low safe working pressure the calorifier is rated at, the safest way and to give peace of mind is to guard the calorifier with a pressure reducing valve.

I don't beilieve that you could achieve this with a gate valve instead of a pressure reducing valve. When all the taps are closed, even the tiniest opening of the gate valve will allow water to pass slowly until the pressure in the calorifier eventually reaches the cut-off pressure of the pump.

 

A pressure-reducing valve would certainly be the most reliable - although I in common with most others do rely on an electrical cut-off switch on the pump; you can at least ensure a backup feature; if you purchase a pump with a built-in cutout switch set just within the capability of the calorifier, but use ALSO a separate (and accurately adjustable) switch such as the "Square-D" switch, and finally have a failsafe by means of the usual pressure-relief valve on the calorifier, then you have belt braces and spare underwear so you should be OK.

[Bones]

Colin.

 

Why all this 'pressure reducing valve' stuff. The Surefow pumps that most boats are fitted with have an adjustable pressure switch, it is an horrible contraption but it can be made to work and much improved if fitted with the alternative low pressure spring. I have also found that water systems function perfectly well at one bar (14 psi). The ratings on calorifier and other items are of course MAXIMUM pressures.

 

Much better to fit a good quality pressure switch and gauge as previous thread.

 

how do adjustable pressure switches wORK?

[John Orentas]

how do adjustable pressure switches wORK?

 

 

 

A pressure switch normally comprises a flexible diaphragm on which the pressure to be controlled acts, that movement is opposed by a spring the pressure of which can be adjusted. An electrical switch (which may control the pump) senses the position of the diaphragm and changes state when the two forces become equal.

If the unit is well designed and engineered a very accurate control of pressure can be attained.

Edited January 22, 2006 by John Orentas

[Big COL]

Colin.

 

Why all this 'pressure reducing valve' stuff. The Surefow pumps that most boats are fitted with have an adjustable pressure switch, it is an horrible contraption but it can be made to work and much improved if fitted with the alternative low pressure spring. I have also found that water systems function perfectly well at one bar (14 psi). The ratings on calorifier and other items are of course MAXIMUM pressures.

 

Much better to fit a good quality pressure switch and gauge as previous thread.

 

John

 

Mute point between between maximum pressures and safe working pressures, I thought I had clarified in my posting the reason for fitting a pressure reducing valve and also covered the reasons why. John you are renowned for keeping boat equipment as basic as possible, you have pointed out that the pressure switch is a horrible contraption, which is the very reason I have recommended protecting the calorifier against any over pressure instances occurring. Bearing in mind that this particular calorifier is low rated by modern standards whereby calorifiers are now tested to 5bar (70psi)

You may have found that 14psi is acceptable to you I personally need more than this pressure to run my shower, and to enjoy the means to have a proper shower, that's a personal thing. When I give advice I look at the facts concerning the particular problem and give the best advice possible, not allowing personal preferences to cloud the issue, if it means using a piece of equipment that is out of the norm then so be it, I am advising people who have less knowledge than myself and I take this into account in my recommendations,

Whatever I advise is something I would do for my own use if it be needed. In this particular case if it belonged to me I would protect it as described. Bones will have to decide what action to take, from the varying and obviously confusing suggestions that have been posted. I have tried to keep it as simple as possible and at the same time giving the maximum protection.

[Keeping Up]

... I am advising people who have less knowledge than myself and I take this into account in my recommendations ...

And yet your recommendation includes a suggestion which I believe would not work and would blow out the calorifier, namely the attempted use of a gate valve to limit the maximum pressure - uness there is some way of using the valve which I am unaware of, in which case I would be most grateful to be educated.

 

Allan

[John Orentas]

I am advising people who have less knowledge than myself and I take this into account in my recommendations,

 

 

A very modest and self deprecating statement.

 

I would have thought there was a very clear distinction between maximum and safe working pressures but in any event pressures in the order of magnitude you mention are completely absurd for a water delivery system. The particular 'horrible' pressure switch I mentioned was the integral one fitted as standard to the Sureflow pump that is why I recommend the fitting of a more sophisticated type along with a pressure gauge in order that the system can be adjusted as desired, 'Instances of over pressure' cannot within reason occur.

Pressure reducing valves are not required in a properly designed system and what 'gate valves' have to do with anything is beyond me.

 

On this post and life in general it usually bad policy to claim intellectual superiority over others.

Edited January 23, 2006 by John Orentas

[Big COL]

A very modest and self deprecating statement.

 

 

On this post and life in general it usually bad policy to claim intellectual superiority over others.

 

It wasn't ever intended to sound as if I was intellectually superior. It is not in my nature to see myself as superior to anyone, in fact the opposite would be nearer to the truth. I continue to ask questions when I need information that is how we learn. As you seek to construe my posting into something that it was not, it may be for the best if I refrain from any further postings on this forum.

[Carrie]

.. if I refrain from any further postings on this forum.

 

 

What!?! You'd better not Col or I for one will be round Sleepy Otter in a flash, demanding help!

 

(sorry, I butted into a conversation there.. )

[Bones]

Good grief. this is rediculous. Must grown ups fight in public? For anyones information Big Col PM'd me with phone numbers should I need assistance.

 

I asked a simple question and have had lots of different ideas about how to do it. The forum is a place where we all have different ideas about to do something, and it certainly doesn't claim to be an evening class of high education. That is the beauty of doing it. I also weigh up everything anyone says when it comes to practicality - I would be stupid not to - and I imagine the chap that did the plumbing on my boat before me thought he was doing a really good job on it.

 

We all have a personal way of doing things, and as far as I am concerned no-one has the right way of doing it unless they are on my boat looking at the system and I trust their skills and knowledge. That simply isn't going to occur here (nor do I expect it).

 

JO - I think you clerly got out of bed the wrong way. To have a go at someone who has clear and consice ideas about how they would do it completely undermines the freedom to ask questions. As for 'intellectual superiority' as you put it, Big Col is right - asking a question about something that someone else might know how to approach it IS 'intellectual superiority' IN THAT AREA. If Big Col were to spend his life on this forum telling others that their ideas aren't helpful, not right etc - on several threads THEN you could point the finger (and some people do it don't they JO). But this is 1 SIMPLE question asked by 1 SIMPLE person trying to learn.

 

Attitudes like this really don't help absolute beginners to boating - those that want to do it themselves but aren't sure. I now have no idea what to do with my calorifier, but I do have some key words and some knowledge so I can ask someone in the flesh. I don't have a pressure releif valve on my calorifier but I do have a 240 link bit (or so the diagram tells me).

 

Perhaps, if you have a personal quib with someones way of doing things it could be constructively put into a systematic conclusive diagram of how your system is wired/plumbed up, so that the questioner (me) has something to go on. Having a go at individual forum members isn't nice - isn't that why David Sch left? Another great loss to the forum.

 

 

I expect I will be banned now....

Edited January 23, 2006 by Bones

[John Orentas]

Bones.

 

It is no good kicking me, in fact I was making a similar point to yourself, for someone to state effectively that "I know what I am talking about so my opinion is the definitive one and that is that" is not in the spirit of a forum.

As for David Schwiezer don't lay that at my door, I was more surprised than anyone when he voted with his feet and I still have no idea why he left us.

[bottle]

 

Bones well said there is too much teddy throwing on this forum.

 

When reading a post remember, you may be reading it in a completely different way as that it was written.(english? where are the teachers when you want one)

 

Guess which one is correct.

[Bones]

Bones.

 

It is no good kicking me, in fact I was making a similar point to yourself, for someone to state effectively that "I know what I am talking about so my opinion is the definitive one and that is that" is not in the spirit of a forum.

As for David Schwiezer don't lay that at my door, I was more surprised than anyone when he voted with his feet and I still have no idea why he left us.

 

 

miss use of quotes - as thats not what he said.

Edited January 23, 2006 by Bones

[John Orentas]

miss use of quotes.

 

 

Good grief what's the matter with everyone this morning, yes you are quiet correct I was paraphrasing.

[Bones]

miss use of quotes.

 

 

just incase anyone has followed this thread and now wonderes about calorifiers.... I have checked a previous forum topic and http://www.tb-training.co.uk/17Bdomwat.html thanks to catweasl (oh dear, have I spelt that correctly!?).

 

This seems to give a very comprehensive approach to things with diagrams throughout.

[John Orentas]

miss use of quotes.

 

 

Good grief what's the matter with everyone this morning, yes you are quiet correct I was paraphrasing.

[Jon]

Guys, I don't claim to know anything about this topic, but once again it seems that old problems with communicating expressly through the written word his reared it's head.

 

I'm going to close this as I don't see what leaving it open will achieve.

 

Jon