LWCO failure

Nyoung

Hello all,

One of our LWCOs recently began leaking by steam. The LWCOs are in service to our Deaerator Tank. To get specific, our unit is the Mcdonnell Miller Series 64 Float-type LWCO.

While they are LWCOs, we have one at the top to act as a high water level sensor which failed. This unit was replaced less than a year ago, and has now failed to the point where steam is passing through the unit. After taking the LWCO apart, it is obvious to see that the point of failure is the spring mechanism. Here is a photo of the "spring" that the internal float is connected to. We know what exactly failed, but we are unsure WHY it failed. Pressures have not been above the rating for the unit (50 psi), and the gasket was in tact. We suspect that it was some sort of chemical fouling on the internals, but are unsure. Has anyone else had similar issues, or some sort of guidance as to what could have caused a failure like this?

Thanks,
Nick

Jamie Hall

Very heavy corrosion failure on that bellows. Water quality?

leonz

I know I am not qualified to ask this, but could you use a McDonald & Miller RB-122-E instead in another port? I have been using this model since 2016 in my coal stoker boiler since I threw the two hydrolevel 3250 plus units/junk to the curb.

Sylvain

Nyoung said:

Pressures have not been above the rating for the unit (50 psi), and the gasket was intact.
Nick

50 psi?
Is this an industrial process boiler?