Do I need to prime a Vetus strainer?

[[3889]]

Am returning to boat this weekend having drained the raw water cooling system. Do I need to prime my Vetus strainer by filling it with the engine seacock closed, as I have done in the past, or will the impeller (Yanmar 3YM30) draw water through? Height of strainer above water line is ~1m.

 

[LittleSister]

I think it shouldn't need priming to fill it with water (the pump should be quite capable of that), but if you prime it it will avoid the impellor in the pump running dry until it pulls the water up through piping and strainer, so why not?

 

[chriswesterman]

On our Bukh 20 Raw water with Volvo Strainer ( similar to Vetus) , I've always got to prime the strainer after draining the complete system. I know that folk are going to say the water pump should prime but when I replaced with a new complete water pump it failed to do so.

On the other hand when staying on a drying mooring with the Engine seacock open , the pump is capable of self priming the system ( ie with strainer bowl + pipe to water pump full)

 

[Len Ingalls]

Why do you drain the system? Why not close seacock,start engine(12-1500RPM) & dump 4ltr of RV (non-toxic ethyl alk) in your strainer,until it comes out exhaust.Leave a/f there,til you use boat again-just re-open seacock.
Alternatively,put a tee & ball valve right before filter with a hose tail,close seacock,insert hose in jug of a/f,open valve & start eng. as above.
If you make hose long enough,& put a strainer on it,you have an emerg.bilge pump. Cheers/ Len

 

[[3889]]

Thanks for replies. Just wondering if it was one less thing to do when I get to the boat after a 700 mile drive. I need to start the engine immediately on arrival to move to a serviced berth. I'll stick with priming it.
TBH, draining and priming seems an easier option than filling with AF.

 

[charles_reed]

Am returning to boat this weekend having drained the raw water cooling system. Do I need to prime my Vetus strainer by filling it with the engine seacock closed, as I have done in the past, or will the impeller (Yanmar 3YM30) draw water through? Height of strainer above water line is ~1m.

I'd recommend priming - you'll probably get some water through, eventually, though at the expense of a shortened impeller life, possibly melted exhaust hose and being deafened by the alarm. I speak with experience of a 3YM.

 

[srm]

On my previous boat with engine and strainer well above the waterline priming was essential. On current boat engine is below waterline and strainer top just above the static waterline so I just open the top of the strainer after drying out to vent excess air. Also, I top up the strainers with sea cocks closed after servicing the raw water pump to provide an intial head. Also, do this as a precaution after laying up afloat with sea cocks closed though its probably not nesessary.

 

[jwilson]

Am returning to boat this weekend having drained the raw water cooling system. Do I need to prime my Vetus strainer by filling it with the engine seacock closed, as I have done in the past, or will the impeller (Yanmar 3YM30) draw water through? Height of strainer above water line is ~1m.

My original Vetus strainer (with 3YM and similar height above WL) occasionally needed priming, or it would take a significant time to suck water through, though it always did within maybe 10 seconds. Traced this to a tiny air leak in the strainer lid from a minute crack. Temporary fix (for several years) was a good smear of silicone grease round the inside of the lid and O-ring. A new strainer unit last year sorted it - at about £80 if I recall. Now water sucks through instantly.

 

[Halo]

I have a 3ym30 and am a bit paranoid about this. One time on re launch my Vetus strainer did not prime - probably because of an air leak around the seal. Now I always prime prior to opening the sea cock. I then make sure there is no leak round the strainer by seeing if the water drains away when the sea cock is opened.