Victoria, British Columbia

Plumbing Information, Advice and Help
Reducing Water Shock

Reducing Water Shock

Posted by wyecoblogadmin

Hammer arrestors are used to stop the annoying ( and sometimes costly and/or dangerous) banging of waterlines when a quick closing valve ("QCV") suddenly closes.When the qcv closes, the water supplying the fixture has a momentum which must be absorbed or else this force will be transmitted to the surrounding piping and fittings. The effect of absorbing this shock is banging pipes and possible eventual failing of fittings (joining materials to be more precise). When this happens - we all know the result - insurance claim and one big mess!

For many years, plumbers would fashion these from short (usually about one foot) pieces of pipe, capped on one end and attached to the water piping close to the fixture with the quick closing valve. Over time, these on-site fashioned arrestors would waterlog and become ineffective. To recharge these pieces of pipe, the water would have to be shut off and drained, allowing air to again enter the arrestors. Dishwashers, fridge water lines and washing machines are the main fixtures that have qcv’s, and should be protected from the adverse effect of "hammer". Todays’ plumbers have an assortment of manufactured devices they install, designed to prevent the hammering, almost all of which consist of a sealed unit holding air above a rubber diaphragm, and in contact with water system below. Even though there are no qav's at a hot water tank, it is wise (and possibly a code requirement in your area - as it is in mine) to install an arrestor on the cold water supply close to the tank. Your hot water tank will have a glass lining (unless it is a specifically non-glass lined type of tank), and the arrestor will help protect the integrity of this lining. When the glass gets small cracks ( also caused by temperature shock), water can seep through to the steel encasement - which will eventually rust and cause a leak. Though off the subject, hot water tanks generally have a average lifespan of 7-9 years, but can last much longer depending on how they are maintained. Drain a gallon or so every couple of months from the valve at the bottom of the tank to get rid of sediment, install a hammer arrestor and if you have relatively hard water in you area - use a softener.

  

 

 
 

 

 

Posted on: 10/27/2009 at 1:08 AM
Tags: , ,
Categories: Water Distribution
Actions: E-mail | Kick it! | DZone it! | del.icio.us
Post Information: Permalink | Comments (0) | Post RSSRSS comment feed
Comments are closed