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How To: Purge a Drum Drip / Low Point Drain / Auxiliary Drain in a Dry Fire Sprinkler System

Procedure to Drain a Drum Drip on a Dry Fire Sprinkler System (also called auxiliary drain, drip leg, low point drain) The Basics: Drum Drips are designed to collect condensation from within dry fire sprinkler systems. Dry fire protection systems are designed to be in areas unfit for a water-filled solution which are subject to cold temperatures below (e.g. 40°F / 4.4°C). Because they are collecting water in cold areas, proper maintenance - like regular draining - is critical to their proper operation. The Components: Some of the components shown may be different than those in your facility. However, most have similar components, functions and procedures to maintain. Contact your licensed fire sprinkler contractor to be sure.

for a free one-page illustrated step-by-step procedural diagram about draining a drum drip on a dry fire sprinkler system in PDF format, please click the image above
 
To get familiar with this part of your Dry Fire Sprinkler system, the parts of a drum drip are labelled on the diagram to the right. An operational drum drip collecting condensation from the dry system should look like the picture above to the right:

✓ Isolation Valve in “open” position ✓ Condensate Relief Valve in “closed” position ✓ Plug in bottom of Condensate Relief Valve
STEP #1:

Slowly close the top isolation valve. This will isolate this drum drip from the rest of the air-pressurized system.

Failure to do so may result in a de-pressurizing (discharge) from the main system!

 Dry Fire Sprinkler System: Drum Drip Drain Procedure
STEP #2:

Now that the drum drip is isolated from the system, remove the bottom plug from the condensate relief valve to allow water to drain through the bottom valve from the drip catcher.
STEP #3:

Slowly open the bottom condensate relief valve to allow the water to purge from the drum drip.

Because the chamber will be pressurized, it may be prudent to use a receptacle to collect the discharged water.

It is not uncommon to hear, see or feel a release of air as the valve is opened.
STEP #4:

To restore the drum drip back to its purpose of collecting condensation, follow the first three steps in reverse, as follows:

4.1. Close the bottom condensate relief valve. This will the pressure within the dry ire protection system. 4.2. Only after the bottom condensate relief valve is closed, slowly open the top isolation valve. This will reincorporate the drum drip into the rest of the system. 4.3. Install the bottom condensate relief valve plug
repeat the steps above until all of the water has been successfully drained from the drum drip.