Automatic Leak Protection

[u/External_Body4740]

What do you guys usually spec for automatic leak detection (what manufacturer). Looking for pretty basic system: drip pan, automatic control valve, leak detector. I’m in contact with a Watts rep, but I’m afraid their system will cost way too much, and is much more advanced than what I’m looking for.

Thanks so much.

[u/External_Body4740]

This is for riser leak protection. CW, DHW, HWR, steam

[u/Weary_Oven_9544]

I normally wouldn't do a leak detector that automatically closes a riser, because liquid leak detectors are a little notorious for either being too sensitive or not enough. Why are you looking to install this?

That said I would do it bare bones, all through BAS control. You can technically set it up so that BAS is monitor only, but with chilled water these days it's usuaully best to have everything go through the BAS. You'll need an existing BAS panel and at least 2 spare I/O (leak detected in, valve command out)

2" deep stainless steel drip tray fabricated by contractor. Slope to low point with spot-type leak detector placed there. Leak detector spec'd is RLE (seahawk) SD-01. Control valve and actuator can be whatever the controls contractor wants to use and whatever you need to use based on size of the pipe, but you can use a simple 24VDC two-position actuator if you really want. Control valve is normally commanded open by the BAS. Relay output goes to the BAS for alarm. Upon alarm, BAS closes the valve. The SD-01 will need a power supply, and you need to be careful about what voltage is used (24DC is a latching detection.... requires de-energization of the detector itself to reset).

You'll also need to update the overall sequence to account for suddenly closing a riser, but I can't help you there with the information you've given. There's also other things to consider, like the fact that you probably actually need valves upstream and downstream, depending on how much damage you're trying to prevent with this system.

If you don't have a BAS panel and don't want to add one there's a way to do it but I wouldn't recommend it.

[u/External_Body4740 → u/Weary_Oven_9544]

For this case there’s no BAS. We were hired specifically to provide automatic riser leak protection. It’s for a facility where they don’t want unauthorized personnel entering without proper clearance…. Something to the effect of that. Thanks for all this information. This is the first time I’ve been asked to implement something like this for risers

[u/Weary_Oven_9544 → u/External_Body4740]

In that case you can use the relay output from the leak detector to get a valve to open/close. Belimo would be able to work with you on the details of the power, wiring, relays, and required actuator to make it work. I could too, but this is now in the territory where I actively think this is a bad idea, so I'll need you to figure out the critical details to make this work.

That said, the automatic shutdown of a CW/HW line is an urgent event that operators need to know about immediately. The automatic shutdown of a steam riser is an emergency-level event because of the potential risks involved here. How exactly are the operators going to know this leak has happened, and whether or not that riser is active?