A FORUM FOR FIRE PROTECTION QUESTIONS & PE EXAM PROBLEMS | SUBSCRIBE NOW
|
A basic question from a non-ITM guy: is the hydrostatic 200 psi or 50 psi over working pressure test simply achieved by hooking up a mobile pump to the system and gauging for pressure loss and visual leakage?
I have not witnessed one of these myself, and wondered if a system design usually would incorporate an extra small outlet for this test or if it's just connected to a main end-cap or something similar. Posted anonymously by a member for discussion. Discuss this | Submit a Question | Subscribe
3 Comments
Yes, hydrostatic test pressure is achieved using a high pressure mobile test pump. Normally an extra outlet is not provided; usually they'll just remove a sprinkler and screw in a 1/2" pipe nipple with a 1/2" ball valve, which can then be easily connected to the test pump. After test pressure is achieved, the ball valve is closed, and the test pump connection is removed. Test pressure is normally read at the pressure gauge above the riser, or downstream of a zone control valve, but it can be read at any system "low point". I usually ask the contractor to switch out the standard riser trim pressure gauge with a calibrated liquid filled gauge, or I just bring my own calibrated gauge as many contractors won't have a calibrated gauge on hand. Record the pressure at the start of the test, and walk the system during the test looking for drops of water on the floor.....looking up at the pipe can be helpful, but I've found it much easier to spot leaks by looking for drops on the floor as opposed to seeing a drop on a pipe fitting. No leaks and no pressure drop = successful test. Be aware that pressure can fluctuate due to temperature changes too.
Dan Wilder
4/17/2019 12:42:39 pm
When it comes to an outlet, we will use a tapped cap with a pipe down at the riser location if the riser is not built or any aux drain location. If the riser is built, we will use a port on the riser check or the Test-n-Drain has the 1/2" outlet for the PRV that isn't installed for the hydro static testing portion.
Mike
4/17/2019 03:08:38 pm
Technically every portion of the system subject to FDC pressure so it should go through the FDC if it is riser mounted. Leave a Reply. |
Free SignupSubscribe and learn something new each day:
CommunityThank You to Our Top
August 2020 Contributors!
Your PostThe ToolkitSprinkler Designer or Engineer?
Get all of our tools, including the Sprinkler Database, Friction Loss Calculator, Fire Pump Analyzer and more: 
Filters
All
Archives
September 2020
Daily
Daily discussions are open-ended fire protection, fire alarm, and life safety questions submitted anonymously for the benefit of sharing expertise and learning from other perspectives. Anyone can submit a question here:
Exam Prep
2020 PE Prep Guide
(Available Now!) 
PE Prep Series
(Available Now!) 2020 PE Prep Series
Current Leaderboard (Click to enlarge) 
PE Problems
Visit July-October for daily Fire Protection PE Exam sample questions.
Solutions are posted the day after posting. Comment with your solutions, questions or clarifications. Please note that questions posted are unofficial and in accordance with NCEES rules are intended to be similar to actual exam questions, not actual exam questions themselves. |
RSS Feed
