What is wrong with this seacock

[30boat]

DZR/Bronze ball valves are about 3x the price of nickel plated brass ones. To give you some idea I paid over £80 for a ¾" and a 1½" DZR ball valve earlier in the year. And they had the 'proper' strong handle NOT the red painted pressed steel ones.
The 'standard' nickel plated brass ball valves(readily available at chandleries) would have been about £25. I got mine from Fox's in Ipswich. ASAP also are very good for DZR/Bronze ball valves. On no account buy 'TONVAL' branded ball valves as they are BRASS - whatever the seller says, and not suitable for use under water.

DZR is still brass.It has arsenic in it's composition, CuZn36Pb2As.For more details http://www.ldmbrass.com/en/product/4-0-0/4-0/dzr.htm

 

[2Tizwoz]

Recently I purchased 2 x 1 1/2" full bore ball valves which are chrome plated and have same handles as op, how can I be guaranteed they are bronze and not brass? The balls are definatly s/s.
Incidently I have to return the valves as I should have purchased 1" as opposed to 1 1/2".
Would I be better to buy all stainless valves, and if so, can I use bronze thru hull fittings with s/s valves?
C_W

Dissimilar metals in electrical contact and seawater is not good. The skin fitting is hopefully bronze. The better solution is a valve of the same material which you then won't have trouble from.

I like ABS plastic where there isn't a potential mechanical damage problem. No corrosion and modest cost if you shop around.

The dezincification problem is discussed in detail http://www.maib.gov.uk/cms_resources.cfm?file=/random harvest.pdf in the Random Harvest report together with difficulties in identifying the true nature of material being sold as brass DZR brass and bronze.

 

[Seanick]

Mixing metals is the issue here.

The water filter looks like a stainless one that used to be supplied by Vetus. They come with an electrical tag (visible) and when new have a yellow sticker on saying 'this filter must be bonded'.

As stainless is more noble than your probably brass ball valve and through hull fitting I would either...

Change the ball valve and through hull for stainless (ASAP Supplies)
or
Change the above for bronze, but fit a plastic Vetus filter instead of the stainless one.
or
Bond the fitting to your anode. However, this in practice usually leads to tears.

 

[MM5AHO]

The handle of the valve with the strainer looks to me to be painted or powdercoated cast aluminium. Not steel, not brass. As ALL paints are porous the aluminium will corrode eventually and corrosion produce of aluminium look like the white powdery stuff in the picture. Any scratch in the paint accellerates the corrosion.

The valve body looks to be plated brass. Can't tell what the strainer is.
But the mixture of metals, and inappropriate ones causes problems.
The ballvalves with the zinc plated pressed steel handles, which often come with a plastic sleeve, are not much good either.

 

[misterg]

T... how can someone be sure that what they are getting is actually DZR and not just a good quality brass with a good copper content?

It's a minefield - most (90%+) of the stuff I've seen in chandleries is utter rubbish (IMHO). I find plumbers' merchants[*] much more useful for valves & fittings -at least they've heard of the term 'DZR'.

DZR fittings often (?) have the initials "DZR" cast into the body. I believe there is a new "CR" mark that means the same thing (the C and the R are joined).

I think the 'CR' thing is a standard, but I'm not sure that the "DZR" marking ever was.

Andy

[*] With the exception of "Plumb Center" who are a bunch or arses (imho).

 

[Clyde_Wanderer]

Well having considered some of the replies on this thread I went along to a specialist plumbing stockist today.
I had a look at their DZR ball valves and they looked just like brass to me, and £17 each for 1" full bore/flow.
Eventually came away with 2 X 1" Crane Bronze (not DZR) full bore 2peice ball valves, at a cost of £81.12p.
They did not have any suitable connectors to use as skin fittings so will have to consider scotia hull fittings, and hose tails.
Will I have to stick with Bronze, or is it ok to use DZR for the hull/skin fittings and hose tails?
Thanks all for your advice.
C_W

 

[VicS]

I had a look at their DZR ball valves and they looked just like brass to me

That probably because it is brass!

DeZincification Resistant brass. A nominal 60:40 brass plus some lead ( 2% ?) and IIRC a little bit of arsenic. But importantly it is heat treated. No knowledge of the details though.

Bronze should be better but DZR brass comes a close second and is used because it is much cheaper.

NO problem AFAIK if you use DZR skinfittings but having paid that much for bronze valves why stick em on DZR skin fittings.

I think A.S.A.P. supplies have gunmetal skin fittings. Check them out. Usually a lot cheaper

( could have got bronze ball valves for little more than half what you paid, looks like £8.60 for gunmetal hose tails and £20 for gunmetal skin fittings)

 

[Clyde_Wanderer]

Interesting, I was in local plumbers merchants today, and notice on my invoice that they describe all brass plumbing compression fittings as DZR, even though they are the poorest quality brass, I mean even worse quality than B&Q's.
I challanged the manager about this and suggested they were just Brass, but he was adament they were DZR.
Makes you wonder!
C_W