Ask the experts
GAS FITTINGS■to install a solenoid gas valve’ (PBO October 2015), the two switches shown are wired in Re David Berry’s article ‘How
parallel, like a domestic two-way lighting circuit such as a hall and landing. The result is that either switch in either position
can turn the system on – there is no standard ‘off’ position for either of them, leaving scope for the gas to be left on if the LED is
not noticed or if it fails. If they were wired in series then both switches would have fioff positions and both would xed on/
have to be ‘on’ for gas to flEither switch could be set to ‘off’ to turn it off.Neil Russell ow.
■installer for LPG, I was alarmed Cosham^ Being a registered gas
at the way this installation was tested. There was no mention of a strength test of the new pipework section, and the size
of manometer used is not suitable for testing LPG. The test procedure should be a fi ve-minute temperature
stabilisation, then a fitightness test. The 30-minute test in the article could have missed a small leak as the ve-minute
ambient air temperature could have made the manometer creep up.Kevin King
■with a Hirschmann connector By email The solenoid valve is fi tted
(the connection block). This is not gas-sealed or waterproof, so it should not be allowed in an area such as the gas locker.
When there is a loose electrical connection in the block, sparks can occur.Tjerk Rodenhuis
By email
Installing a solenoid gas valveReaders express concern over an article in the October issue – and explain how to fi x it
The solenoid valve used in PBO’s October feature may not be suitable for boats, according to our gas expertPETER SPREADBOROUGH
REPLIES: solenoid valve used as suitable for a recreational vehicle (RV), but I have concerns that it is not suitable Hamilton’s advertise the
for a marine environment.of the coil will corrode and the valve will fail to operate.From experience, the terminals
are not encapsulated, the valve cannot be considered flor intrinsically safe for gas.Secondly, because the terminals ameproof
use the valve will get very hot. This can easily exceed 60°C, which is the limit to which flAdditionally, when in prolonged exible hose
should be exposed.be like the one supplied by Nereus Alarms of Poole. This valve is A more suitable solenoid would
sealed in resin to make it waterproof, flintrinsically safe for gas. Also, a nice feature of this product is that ameproof and
the power consumption is reduced once the valve is open to a mere 0.2A at 12V (compared with around 1A for the valve used in the
feature) so it does not get hot.The procedure for soundnesstesting is laid out in PD 5482-3:2005 Annex C.6.2. In a
nutshell, it should be tested with air at a pressure 45mb, left to stabilise for fi ve minutes and then
tested for two minutes with no discernible drop in pressure. In the article, the installation could not have been checked at 45mb
as the manometer is only calibrated to 30mb.DAVID BERRY REPLIES: The
valve I used is a type VMR010, manufactured by Elektrogas who are a major supplier of gas solenoid valves and who kindly
supplied me with information on the Standards their units meet.supply clearly indicates the The online datasheet they
connector housing is rated as IP54 which, as Peter Spreadborough and Tjerk Rodenhuis agree, is not suitable
for use in the gas locker of a boat, due mainly to the highly corrosive salt-laden atmosphere andpotential for exposure to leaking gas. A solution is to replace the electrical unit with a sealed IP67 one: an internet search turned up
a number of suppliers who can provide a plug-and-play replacement, and this is the course I shall follow to make the
valve more safe.that it is normal for the solenoid to The datasheet also indicates get hot. After
and, sure enough, the coil Peter’s comment I measured mine
valve body, presumably was 86°C. However, the
conduction path, was 43°C. cooled by the metallic
c nsidered suitable why this valve is Perhaps we should question
in this respect for an RV but not for a boat? The Nereus valve seems an ideal solution, but at a rather high price.
procedure I used, the Standards cannot be argued with: so anyone who is interested in carrying out a While I have faith in the testing
gas test after replacing a hose, cooker or anything else should follow the procedure Peter and Kevin King describe. I shall be
re-testing my installation. My method was based on what I was taught a long time ago when I worked for the now defunct Wales
Gas, and that was natural gas.two switches in series rather than the standard two-way Neil Russell suggests wiring the
confi guration I used, which relies on having an LED as an indicator.look at the switch position rather It’s a good idea if you prefer to
than rely on an LED.(^50) Practical Boat Owner 592 October 2015 • http://www.pbo.co.uk
David Berry demonstrates how he went about connecting a solenoid valve to his boat’s gas supplyHow to install a solenoid gas valvethe only way to do this on a boatOMoody’s gas supply. Sensibly, where the gas pipe is buriedSTEPSTEPBYyear was the need to fit a remote shut-off valve to our ne result of our boat survey last
indicator to the circuit to remind us to switch it off when we hadTherefore, I added an LED finished with the cooker. It also seemed sensible to have two and be controlled from a switch (orlow-pressure side of the governor switches) near to the gas appliance it feeds – in our case, the cooker. to be fitted in the gas locker on the the valve is on it draws about 1A. valve is failsafe it requires current to operate it, so that all the time behind all sorts of obstacleswas to fit a solenoid valve.A drawback is that because theThe requirement is for the valve
Installing the valve with this feature that still have torelay triggered by the gas alarmactivated, but there were issues to disconnect the gas if the alarmbe resolved.cooker – so that if a problem didswitches – one either side of theoccur the gas could be isolated from whichever was convenient. I also considered adding a^
the bottle via a strange block which fulfils thefunction of an elbow, a reducer and a support.tube run through a PVC hose to the cooker – our only gas appliance. The inlet of the a compression elbow on the left to a coppergovernor is through a ¼in rubber hose from^1 The Moody fit is a standard governor (thisone was fitted new in 2011) connected by (^) decided to leave the support elbow on the always use new fittings if you can. I also inlet of the governor.not a great solution on a gas line: you should BSP elbow being cleaned up ready for reuse, improvise. This is the^3 ⁄^8 Then I discovered the compression fitting wascopper pipe was left protruding into the locker.in, not 10mm as I had thought, so I had to^2 The first thing to do was to removeeverything until only the end of the^38 in compression to ¼in⁄^ stayed sane. to the toe bone, or is it the neck bone? Layingcompression elbow. The knee bone’s connected^3 cast in the body to indicate the direction of flow.everything out like this was the only way I^8 ⁄^3 in BSP, which is also the thread on the governor has ½in BThe gas valve has ¼in BSP ports, but the NOTE: the valve has an arrow SP ports bushed to^3 in^8 ⁄
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