Rok trajanja kovinskih iztokov?

[admin]

Ventilov skoraj ziher ne dela, ker to kot je napisal CAR je kar resna zadeva... Dela pa usise, izpuste... To pa je navadna "drejarija" ali po slovensko struženje.
Ventil pa se kupi. Absolutno je medeninasti usis krepko boljša izbira od inoxa. Inox za to ni primeren (razen nad vodno linijo), se pa na policah dobi, ker povprečen morjeplovec nima pojma o koroziji, materialih, potencialih in podobno in je tako na polici inox zakon, ker se tako lepo sveti... Če ste pametni, ne kupujte inox ničesar za pod vodno linijo!

[mirante]

Kako pa dolgoročno po teoriji paše skupaj kombinacija medeninastega izpusta in kovinskega ventila (zasuna)? Zdi se mi, da je vsaj kroglični del ventila iz inoxa, v sporočilih na morjeplovcu pa sem prebral, da medenina in inox ne gresta najbolje skupaj.
Meni v 30 letih, kolikor imam jadrnice, nikoli ni puščalo, korodirali pa so mi ventili, da sem jih vse bolj težko zapiral in sem nato slej kot prej polomil ročke.
Razmišljam, da bi tako za podvodne kot nadvodne iztoke vmes v cevi namesto kovinskih dal plastične ventile. Enega sem pred leti že tako zamenjal in še ni zarjavel .

[francelj]

Ventil in vsis sem menjal pred tremi tedni. Tudi meni se je zdelo, da imajo medeninasti ventili kroglice iz nerjavnega jekla, ker se tako lepo svetijo, zato sem se še posebej trudil iskati takega, ki bi imel tudi kroglico iz medenine, ker jo je očitno imel stari ventil.

Potolažilo me je tole iz

http://www.kovina.si/default.asp?mid=sl&pid=nasveti

Krogelni ventil je sestavljen iz naslednjih elementov:

1. ohišje: kovano iz medenine Ms 58 (CuZn40Pb6 - po DIN 17660); niklano, neniklano.
2. krogla: kovana iz medenine Ms 58 diamantirana in kromana
3. tesnilo krogle: PTFE
4. tesnilo osnove: PTFE, EPDM, NBR
5. ročica: silumin ali jeklena, plastificirana ali iz plastike

Tisto kar se sveti na ventilu ali v ventilu je krom ali nikelj in ne jeklo.

Barva ročice označuje namen uporabe. Rumena za plinske ventile, ki so uporabni tudi za vodo, le da ustrezajo strožjim kriterijem tesnenja in niso namenjen visokim tlakom, zelena za pitno vodo, rdeča za vse ostalo...

To je vse, kar so me naučili v trgovinah in na straneh proizvajalcev. Upam, da bo ventil zdržal vsaj toliko, kot je stari

Aja, ventil sem kupil v Merkurju, medeninaste kose cevi in tesnilno nitko pri Pergarju v Izoli, vsis pa v Marine System Koper. Samo zato, da ne bi bil kdo od teh ljubosumen na drugega

[mirante]

Super, hvala vsem.
Zdaj sem dobil še zadnjo manjkajočo informacijo in se lahko lotim dela. Le zima se mora še prej končati .

[andrejv]

Zanimivo je prebrati tudi tale blog o obnovi HR 46. Med drugim se dotakne tudi odtokov. Sicer pa je to zelo zanimiv blog o obnovi rabljene barke.

Treba je malo poskrolati nekje na sredo članka:

http://reginasailing.com/the-engine-room/


Tu pa še direktno tekst tega dela:

Sadly enough, most yards in Europe use standard brass as their through-hull material these days. Brass contains zinc, which is a metal that is easily “eaten up” by galvanic corrosion. This is also the very reason why zinc is used as anodes in order to protect other, more noble metals onboard. The zinc is scarified and must therefore regularly be exchanged in order to protect, for instance, the propeller or the bow thruster. However, I don’t want to use our though-hulls and sea-cocks as anodes!

Possibly, this is only a psychological factor. Anyway, I would not sleep well knowing that my through-hulls contain zinc. Interestingly, I am not alone with the opinion that brass should be avoided under the waterline and that bronze is the material to use instead. Especially in the United States, it is much more common to use through-hulls made of real bronze, especially on high-end yachts. Bronze is somewhat more expensive than brass, but does not contain any zinc at all. In the old days, it went without saying that all boats were equipped with nothing but bronze under the water line. Why not any more today?

I have spoken with several yards about this issue and I get widespread answers. Some renown yards claim they do not know of any problems with their through-hulls. Others say their brass is of a specially good type while they do not want to reveal the exact type of alloy they use. An answer I find understandable is that if they would change (back) to bronze today, the yard would get into a situation where it needs to explain to customers why the previously used material suddenly is considered not good enough. Finally, many yards don’t want to change something that – in their eyes – has worked fine for many years, and think this debate of brass contra bronze is merely academic. Again: understandable.

So, all good reasons, but not on my boat, please! It might work well on most yachts, but boats get older and how many owners are aware of the fact that brass has a limited life-span? Surfing the internet, it is becoming an increasingly hot topic among discussion groups, since many sailors do not know what they have, brass or bronze. Or even worse: Many boat-owners on the forums have been under the impression that their through-hulls were made of bronze but now learn that they are made of brass instead. I think it is better to make no secret out of it, and to say how it is. After all, your through-hulls is a very important safety issue.

And if you are like me and only believe in the best, then it is better to change the through-hulls. It might not be necessary on your boat, but I don’t want to take the risk on mine.

As we could see on our own boat, Regina Laska, brass can lead to problems, nevertheless. In one case we could kick off one of the through-hulls with our bare feet, so weak it had become. Some more years, and it had certainly become a threat for the boat’s safety, even without kicking! Strangely enough, many of the other through-hulls still had a fair amount of material left. But how can you tell which through-hulls will last and which ones will not? I would strongly suggest any boat with through-hulls older than 15-20 years to check these or, even better, to change them.

The weak through-hull on Regina Laska might be a result from the fact that this particular boat had possibly been connected to shore-power for too long without the so very important isolation transformer installed? If you buy second hand, how can you know for how long the boat has been connected to shorepower? And which harbour has a faulty earth leakage, anyway?

For me, a good solid through-hull is a very important safety feature and, in all honesty, I cannot think of any reason in this world why not to use the somewhat more expensive but so much stronger bronze alloy for underwater through-hulls.

[andrejv]

Absolutno je medeninasti usis krepko boljša izbira od inoxa. Inox za to ni primeren (razen nad vodno linijo), se pa na policah dobi, ker povprečen morjeplovec nima pojma o koroziji, materialih, potencialih in podobno in je tako na polici inox zakon, ker se tako lepo sveti... Če ste pametni, ne kupujte inox ničesar za pod vodno linijo!

Kot lahko prebereš v blogu o obnovi HR46 je menda prava rešitev bronze (bron ?) in ne brass (medenina).

[admin]

Jap, imamo bron in med. Obema je osnova baker, sta tudi podobna za videti, vendar pa precej različna. Oboje je zlitina! Med ali medenina (mesing nemško) je zlitina bakra in cinka! Bron je zlitina bakra in ostalih elementov, načelno brez cinka ali malo cinka... Imamo različne brone, kjer prevladujejo različni glavni elementi v zlitini, je pa najbolj pogost kositrov bron.
Bron je seveda še bolj odporen in pa predvsem ima precej višjo trdnost!

Je pa tako, da se med v slani vodi tudi odlično počuti! Problem medi je samo na stiku zraka, če pa je potopljena, je zakon!
Zato iztoki pod vodo med, iztoki, izpusti nad vodo, obvezno polirani inox! Če pa dobite namesto medenine bron, pa je samo še boljše, vendar pa ne drastično!

Nisem utegnil vsega tega prebrati, bom, ko ujamem malo časa...

[SR 290]

Baker+Cink= medenina
Baker+kositer=bron
In potem Balaševič zapoje:"Sve su ostalo nijanse."



Kaj pa inox krogelni ventili, ki so namenjeni pari in kislinam?
Mislim, da je material A4 in je precej mehak. Tesnila so karbonska.
vgrajevali smo jih v ene druge zadeve in nam jih je kar nekaj ostalo, zato sem ga dal na dotok vode v wc školjko in na iztoke iz maceratorja, umivalnika v "kuhinji" in umivalnika ter tuša v kopalnici.
Naj zamenjam z medeninastimi ali pustim?



@Admin;
Mislim, da se aluminijevega brona morska voda sploh ne loti.

[marjan5]

Tud sam moram letos zamenjat nekaj izpustov in ventilov na jadrnici. Odločil sem se za Inox. Res bi bil najboljši bron, vendar je taprav bron tako drag da si ga ne morem prvoščit. Inox je po moje veliko boljši od medenine dokler je samo pod vodo ali samo nad vodo, ne mara pa zelo velike vlage. To se pravi neka vlažna obloga pod katero pride tudi zrak, takrat pride do nevarnosti piting pa cracking korozije. Medtem ko je mesing zlo občutljiv na galvaniko in slano vlago, ker se raztaplja zink to vidite da postane namesto rumen ,rdeč tak materjal pa postane krhek in porozen.Ponavadi se na ventilu nabere kup soli pod njo je pa mesing rdečkast. Mesing bo zdržal kakih 5-10 let za inox ne vem natančno, bron pa čez 30 let.
LP Marjan

[francelj]

Med iskanjem sem edine bronaste ventile našel v Motomarine katalogu. Na žalost ne morem videti cen v katalogu, še manj pa vem koliko bi me stali po vseh pod roko in na počez scontih.

[od kapitana zena]

Med iskanjem sem edine bronaste ventile našel v Motomarine katalogu. Na žalost ne morem videti cen v katalogu, še manj pa vem koliko bi me stali po vseh pod roko in na počez scontih.

Pokliči, Vito (don).Je moja stalnica. Govori lepo zlovensko, ker je mama Slovenka.

[bostjanpar]

Nekaj strokovno podkrepljenih informacij o iztokih z primeri:

http://coxengineering.sharepoint.com/Pa ... ronze.aspx

[EL CAPITANO]

Kje pa kupujete bronaste ventile?

Z rosfrej ventilom na ispustu za wc nimam dobrih iskušen. Zamenjan pred 2 leti kupljen v motomarine zablokiral. Stari bronasti držal 15let.

Mirante,

kakšni so to plastični ventili ?

[mirante]

Ventil je narejen kompletno iz plastike. Je malo bolj masiven, kot so kovinski in se vanj lahko privije nastavke za cev (prav tako kot v kovinske ventile).
Pred leti sem ga za iztok WC-ja poskusno kupil v Kamm-u in mi deluje brez težav.

[andrejv]

Kje pa kupujete bronaste ventile?

V VETUS katalogu se jih najde..