Self draining heat exchangers, why not?

[sdowney717]

with the recent cold, I just remembered to drain 5 heat exchangers.
So why cant some of them be self draining?
So the discharge to the rest of the system is at the lowest point of the heat exchanger


It also bothers me that the 2 engine heat exchangers when drained splash salty water onto the front motor mount. I think some changes would help that regardless.
Part of the issue is the drain doubles as a zinc anode. So could involve drilling another hole for a drain and a connected tube, such as a valve and hose.

[catalinajack]

Originally Posted by sdowney717

with the recent cold, I just remembered to drain 5 heat exchangers.

So why cant some of them be self draining?

So the discharge to the rest of the system is at the lowest point of the heat exchanger





It also bothers me that the 2 engine heat exchangers when drained splash salty water onto the front motor mount. I think some changes would help that regardless.

Part of the issue is the drain doubles as a zinc anode. So could involve drilling another hole for a drain and a connected tube, such as a valve and hose.

Guess I was lucky when I replaced the exchangers on my Lehman 120s. The ones I got had two threaded ports on the bottom, one of which is used to supply the stuffing boxes. The anodes are on top.

[sdowney717]

Originally Posted by catalinajack

Guess I was lucky when I replaced the exchangers on my Lehman 120s. The ones I got had two threaded ports on the bottom, one of which is used to supply the stuffing boxes. The anodes are on top.

I think this spring will add some changes by silver brazing on some fittings.
I had to repair these years ago by brazing when I got the boat, so I know all about them. Anode on top is fine, what I really want is an improved draining method. My repair was for cracked tubes. May have been caused by freezing when owned by PO.

They are made by Sendure.

I have underwater exhaust, so I rigged a tell tale coming off the engine-trans heat exchanger out the back of the boat with a 1/4" tube.
So I suppose that tube could connect on the main heat exchanger instead, or even be combined into the other heat exchanger to drain both together.

I should turn the drain of the engine-trans heat exchanger into the tell tale tubing. I had done it another way.

Does anyone think a 1/4 inch tube is sufficient for a drain ?