Thread: Testing LDH with Storz couplings
09-14-1999, 08:32 PM #1FIRE549Firehouse.com Guest
Testing LDH with Storz couplings
We have just purchased 1000' of 5" hose with storz couplings. I would like some suggestions on the best (safest) way to pressure test this hose. We will follow NFPA guidelines (300' layouts, 200 psi for a min. of 5 min. etc...)What I'm looking for is how various departments set the test procedure up. Thanks in advance!
09-16-1999, 10:59 PM #2KenNFDFirehouse.com Guest
When testing any hose we are concerned with the pressure, not the flow. During hose testing from a fire pump, we use a hydrant gate with a small (approximately 3/8") hole drilled in the gate. This allows the hose to be pressurized. In the event of a failure, the hose end does not flip around as the flow is only a few GPM.
Typically, the hose is filled with water, the gate (with the hole) is closed an the testing process begins.
We modified our procedure slightly during our hose test last year. We laid out the entire 1200' of 4" hose on a slight incline and tested it in one shot.
Yes, I know NFPA states 300'. NFPA cannot give a reason for this except it is "safe and managable" For us, we are fortunate to have a dead end road in an industrial park to do a 1200' hose lay. It is managable for us. There is no facts that back up the 300' hose lay as being safer. We, as many other departments, routinley lay over 300' of LDH and pump it to within 25 PSI of the test pressure.
The jackets are marked at the couplings with Magic Marker. All personnel wear helmets. No one is allowed within 15' of the hose while it is under test pressure.
The advantage of the slight incline:
After the test, close the pump discharge and open the nozzle. The hose will drain and the a slight negitive pressure in the hose above the draining water column will cause the hose to collapse flat-easy for pick up with out using the rollers.
Captain Naugatuck FD,CT
Instructor,CT Fire Academy
[This message has been edited by KenNFD (edited September 16, 1999).]
09-17-1999, 02:19 PM #3Dalmation90Firehouse.com Guest
I like Ken's idea on the flow limiter!
We're also fortunate to have a fairly isolatable area to do our testing. We have 5000' of 5" on one engine, 1500' of 5" on another, and 1200' of 4" on another. We either lay a single long 5000' lay, or we test in approx. 1000' lengths.
On the subject of LDH...all of ours passed for 10 years...and now we're starting to have some that doesn't (which is OK, and the reason you test it in the first place!). Most of the time we can trim around it, and turn a 200' length into a 180' length (or whatever!). And we've implemented a plan with the Town's Capital budget which will replace all the hose on a rotating basis every 15-20 years by buying 500 or 600' new each year and retiring lengths that aren't passing.
Our handlines are tested using the 300' lengths or less, and a high pressure washer/hose tester unit.
09-20-1999, 03:05 PM #4FIRE549Firehouse.com Guest
What are some ways you purge the air in the 5" hose line?
Thanks in advance.
09-21-1999, 04:57 PM #5Dalmation90Firehouse.com Guest
Purging air...for hose testing, we have valve and nozzle on the far end...bleed air, flow water, shut the valve, build the pressure.
For re-packing, our hose is on a reel system, and we use a "anchor" man who helps hold a little tension on the hose -- we pickup a length at a time, the reel pulls it in, most of the manpower passes the hose hand over hand just to keep it off the ground, and the anchor walks in to keep the coupling straight to let the air bleed out.
09-21-1999, 06:16 PM #6FIRE549Firehouse.com Guest
I guess I'm not getting my point across. I've been testing hose for several years and know the operation. I just thought there would be something particular to purging the air from a five inch hose line. What we need in my department are the correct valves and adapters to complete this evolution. We have the ability to deliver water from the hydrant to the pumper but cannot relay water right now. I understand we have ordered the needed items to do this.
Thanks for you time!
09-22-1999, 09:53 AM #7Bob SnyderFirehouse.com Guest
We've been using LDH with stortz couplings in our area since the early 1980s, and everything that's been said here sounds about right to me. As far as bleeding air out of the lines, we just put a distributor valve (the same one we use at tanker fill sites) on the end of the lay, start with 40-50 psi at the panel and a valve cracked open to flush the air, then close the valve and jack up the pressure (just as Dalmation described).
The only difference that the stortz couplings make (as far as I know) is that you need to make sure that you have no twists in the line that will cause the couplings to spin apart as the line is pressurized. This isn't just a testing issue, though. This is an everyday-use issue. Of course, if you have locking couplings, this isn't a problem either.
09-23-1999, 10:28 AM #8FIRE549Firehouse.com Guest
We have ordered the valve to help us purge the air and to our credit we do have the storz couplings with the locks. The locks, from a safty issue, make me feel a lot better. Thanks!
09-23-1999, 12:41 PM #9EPFD-ALFirehouse.com Guest
We've been using 5" w/storz fittings for 10-12 years. (Carry 1500') Great stuff!
While I REALLY don't mean to knock anyone in the fire service, I was very surprised to read that some of us are still concerned that twists in LDH can uncouple hose.
Anyone currently using LDH storz couplings without thumblocks is looking for trouble.
Thumblocks may be a pain in the butt, (especially in cold icy weather), but they're worth their weight in gold.
Please, PLEASE get your LDH storz couplings retrofitted ASAP ($175-$200 pair) before something bad happens.
09-30-1999, 12:14 AM #10SOMLFirehouse.com Guest
My Dept. has been using 5" w/storz couplings for about 15 years now. We test every year 5000 + feet in 300 foot section in a large parking lot. We purchased from Harrington a air bleed end cap and use a 2 1/2 to 5" adapter on the engine.
The easiest way we have found to drain the hose is by having 2 ff walk with a 6' pike pole under the length of hose while another ff acts as an anchor.
5" might be tough to work with but hey, when you need water, you NEED water.
10-02-1999, 01:25 PM #11FIRE549Firehouse.com Guest
Thanks! How do you get in touch with Harrington for the bleeder cap?
10-02-1999, 02:19 PM #12EPFD-ALFirehouse.com Guest
03-19-2008, 12:31 AM #13
- Join Date
- Sep 2003
i believe the 300 foot limitation has to do with the water capacity in the hose. at test pressure, a failure would still flow about a gallon per foot depending upon size.
03-19-2008, 02:20 PM #14
WOW!!! Resurrecting a 9 year old thread?!?! That has got to be some kind-of record!!!I can't believe they actually pay me to do this!!!
One friend noted yesterday that a fire officer only carries a flashlight, sometimes prompting grumbling from firefighters who have to lug tools and hoses.
"The old saying is you never know how heavy that flashlight can become," the friend said.
-from a tragic story posted on firefighterclosecalls.com
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