hot water boiler water feed question

clammy

Recently i was asked to install check valves on the water feeds for some hot water boilers that i service in a commerical building .Usually i install a swing check ,backflow preventor and pressure reducing valve and then a shut off for service .Well the insurance co sent us a diagram where they want the check installed as close to the boiler as possible .They are not showing a backflow nor prv instaed just a swing check and a plug cock  or hand valve .Am i off base thinking that these guys are taking this out of content being the diagram they sent was from nj  dept pressure vessel and for me it looks like the  state diagram is for a water make up off a da tank /make up for a steam boiler.There really is kinda of no talking to these guys they want what they want and really have no clue being they missed the fact that none of these boilers have manual reset hi temp limits and not all of them have lwco .Also wondering what effects a swing check installed on a outlet of  a prv will the prv be able to sense a drop in system pressure and feed or will the swing chek prevent it from doing so .I have been already told to just do what they say and make out the bill but i don't want to be left holding the bag .Thanks peace and good luck clammy

STEVEusaPA

ugh......

I hate these situations.  They think they know better then you, even though they are getting their information from the wrong source.

I think you're on the right track.  I would send them a letter, basically what you said in this post.  Attach a diagram of the your way (the right way).  Then ask them if they are willing to sign off on doing it their way (the wrong way), when either the system breaks down, or any property damage.  Because 'the experts' get real dumb after the fact (when they lawyer up)  Also ask at support for the PRV manufacturer, and tell them what they want you to do.  I'm sure a letter from the manufacturer will (should) carry some weight.  You could even quote some of the Massachuettes State Fire Code (as one example) about the manual reset hi limit, and lwco.

You know, if something goes wrong, some @#$%@% lawyer will be so happy in court when he gets to quote his favorite line, "You're the expert.  Shouldn't you have known that....."

Of course you have to balance that with the reality of if you don't do it, they'll get someone else, and maybe you lose a large/long time customer. 

As far as the swing check, not ideal, but I think if the pressure is lower on the outlet side, it seems the check would allow the feed to add water, but why take a chance without the LWCO, or better yet, tell them the only way you'll do it their (wrong) way is if they allow a LWCO, AND a manual reset HI limit.

Good luck.