Watermaker pump relief valve

[Hoghead]

Is it necessary? My output pressure is controlled downstream of the membrane via a simple needle valve. Unless the membrane or this valve is blocked up I do not see how the pressure could spike? Is a SS valve required? I see that at least one Vendor seems to use a brass one right at the pump unused second outlet so no flow through the valve

[colemj]

Ours is brass. I don't think they are required as long as you monitor it occasionally while using. It is, after all, just a "oh crap" last resort thing and not part of normal operation. In seven years of operating ours, I have never had it pop off.

On the other hand, they are inexpensive.

Mark