I work at a hotel and we are having problems recently with pipes hammering, I need some help, thank you.?

Question

My boss, the chief Engineer here, called in a plumber and the plumber suggested among other things to check the mixing valves on the showers, so my boss now has us checking the mixing valves in all 76 rooms on the 1st and 2nd floors, the only 2 floors of 13 where the noise is heard. I'm not a plumber by any means, but I do have a general knowledge of plumbing, and I just cant fathom how turning off the supply to an idle mixing valve in one room is going to stop the hammering in all 76 rooms. Has anyone dealt with commercial plumbing? Does this sound reasonable to you? Do you have any idea what could be causing the noise? Is there any way to fix it without draining the entire building?

I have been working here for about 17 months now, and when I started the noise was nonexistent, after a couple of months I got one complaint of a loud noise, then another from a different room a few weeks later, and it has snowballed from there to include almost every room on the 1st and 2nd floor

Answer 1

You have half of the problem solved...hammer Whats happening is a water hammer and it can be created after the installation is finished by a few different ways. One of the biggest ways after the job is done and working is some of the straps at certain stress points came loose and you get a chain reaction with straps coming off the walls causing your water hammer Your main pressure regulator valve could have been messed with by the landscapers.. they're real good at messing with the main regulator. if its just happening like in the morning or just in the afternoon...could be water adjustments by the city.but look into new construction around the plumbing or straps tearing off in this aplacation..mixing valves would be my last guess.hope this helps.

Answer 2

Hi, water hammer is usually caused by 2 things, the opening and closing of a faucet abruptly combined with the vibration of a faucet valve which together causes a vibration transfered along the pipe work known as Water Hammer.
The best way for checking for this is to close all normally open faucets, eg Washing machine, dishwasher and toilet supply forcets. Then by using the faucet that causes the water hammer, turn these normally closed faucets on one at a time to find the problem faucet valve.
Note the faucet causing the hammer and the faucet with the faulty valve may not be near each other which is one of the problems with water hammer and why most plumbers will avoid trying to fix the problem.
Another suggestion is to check the pressure limiting valve to the building or the problem areas and change to one with an appropriate psi rating if necessary especially if the water supply to the building or problem area has been improved recently.
Good luck, Warren.

Answer 3

You can buy air hammer stoppers (says my hubby) You can buy them at Home Depot.

I just found this article:
What causes noisy pipes, and what can I do about it?
Noisy pipes can be caused by several factors. Let's start with what is commonly known as water hammer. Water rushing through the pipe and out the faucet moves with speed and force. When you shut off the faucet, the water flow is brought to an abrupt halt. But that energy has to go somewhere. So normally in the wall behind each hot and cold faucet is an air chamber in the pipe. It used to be about 10 inches of pipe soldered vertically. Then when the rushing water was stopped it would push up that vertical pipe where it would hit a cushion of air in the pipe. And that would prevent the water force from causing the pipes to rattle, or hammer. Now there are commercial air cushions that are attached to the pipe in the same place and do the same job.

Hammering can develop because over years the air in that little vertical riser is lost, and thus the cushioning effect is lost. You can often correct this by shutting off the main water, opening all faucets and then draining the whole house from the lowest faucet. When you restore water, air will be again pushed into the risers designed to prevent water hammer.

Another cause of plumbing noise is a loose pipe under the house. The flushed water moves rapidly and in large volume and can cause a pipe to sway, setting up a rattling effect. Drain pipes are usually suspended from the floor joists under the house and a little stabilization may be all that is needed. By crawling under the house with a flashlight while someone flushes the toilet, you should be able to find the source by listening and looking.

Whistling or squealing in pipes is often caused by a worn out washer in a faucet or valve. A common source of this squealing is in the valves that connect to the washing machine. If you notice the squealing sound comes when the washer is working, you have an easy solution. First, shut off the valve and check the washers in the hose. Replace if they look worn or cracked. If that isn't it, shut off the house water and repair the faucet. One of the faucet's washers is likely worn or the valve seat is worn, causing water to be forced through a smaller opening and setting up the noise.

Another source of squealing, particularly when it seems to resonate through the whole house, can be either the main shut off valve for the house or the water pressure regulator. For the main shut off, turn off the water at the street valve first and then replace or repair the main house valve. If that isn't it and you have a pressure reducer on your incoming cold water line, it may be in the reducer's manifold.

Yet another noise problem can come from the toilet. If, after flushing, you hear a banging or rattling at the end of the fill cycle, then it is likely that the ballcock assembly, which controls the fill process, is worn. Depending on the style and how new it is, you might be able to repair it. Otherwise, replace it with a better one. "

Answer 4

It sounds like the hammering is being caused from a fluctuation in water pressure ... so how do you narrow that down? I have to agree that it could be the mixing valves on one or a few of the showers .. I would also check the circulating pump to make sure they are operational.

How old is the hotel? If fairly new, you might be able to isolate a bank of 6 or 8 rooms at a time. Are there shut offs for a bank of rooms?

You might also do flow tests in each room to see if there is an inconsistency. You can unscrew the shower head and screw on a reducer that has a pressure Gauge at the end of it to test the pressure. We do this at Marriott. Maybe you might be able to tell if there is a room with fluctuating pressure.

Answer 5

my company has done many hotels the mixing valves are not the problem. If it is indeed water hammer ------ water hammer happens when the flow of water stops suddenly with no place to go ie.. washer machines that have a solenoid valve to turn off the water supply. My guess would be to check the expansion tank(s) at the water heaters. Most of them have a baldder in them that you can adjust the pressure in it. I would ck and see if there is any air in it and if so how much is in it. If one of the tanks have gone bad then you will have to replace it or you may have to install a larger one depending on the size of the system

Answer 6

Your pipes have air in the lines.You may be able to bleed out the air at the cooling tower or go to the top floor and release the air from one of your HVAC cieling units.Some buildings have a bleeder valve located in the attic on top of the building.Having the systems air removed will make the ceiling units work more efficiently

Answer 7

Hammering pipes is sometimes a symptom of an airlock. Check the main leads and try bleeding off the system to see if that solves the problem.
Sometimes those plumbing gremlins can be very devious! Good luck to you.

Answer 8

It's called water hammer and can be the result of pressure problems, air in lines, expansion of differnet type pipe material (or improper pipe material) with outside air temperature--assuming the pipes are on the outside walls, etc.

When it occurs here the first thing I do is bleed the lines of excess air. I haven't a clue how to do it in a multi-unit complex. You need a plummer with many years commercial experience.

http://www.plastomatic.com/water-hammer.html
Here's a website that explains it in engineering terms:

Answer 9

check your domestic water expansion tank it is probally waterlogged. otherwise look for abrubt changes in water flow such as a check valve swinging shut when a pump shuts off.
doubt is is mixing valve issue. Chief probally does not know what to do so he ran you all off to stay busy while he scrambles.

Answer 10

The normal solution is to put a "shock absorber" in the pipe near the valve. ( I 'm just a lady- but you have great advice above).