About High Pressure Cylinders DID YOU KNOW

Written March 2005

I am surprised at how few dive shops that perform scuba repair have torque wrenches. There are certain fasteners in scuba equipment that absolutely require the use of a torque wrench for installation. One of the most frequent uses of a torque wrench is to install valve burst disc safety bodies (plugs). These fasteners are hollow, and often made of chrome-plated brass, which inherently do not posses high shear strength. Additionally, the torque values are relatively light, in the range of 50-125 in/lbs. for most burst disc safety bodies (depending on the manufacturer). Over-tightening of these fasteners can result in the failure of the fastener, which would be considered a catastrophic failure of life-support equipment.  (Editor’s note: DOT requires burst discs to be set at hydro test pressure with a tolerance of +0% to -10%.  Torquing to the manufacturer’s recommendations is your only practical way to ensure this setting).

When purchasing a torque wrench, there are several considerations to bear in mind. One single torque wrench will not adequately cover all torque specifications. Choose a torque wrench with the appropriate scale for the specification. Torque wrenches are only accurate from 20%-100% of their scale, in other words, the first 20% of the scale is totally inaccurate. If the torque value is 50-55 in/lbs., do not chose a torque wrench with a 0-1000 in/lb scale, since 0-200 in/lbs of the scale is unreliable. There are two basic types of torque wrenches to choose from; dial and click-stop (I am not considering beam-style wrenches, as they are generally too inaccurate to consider reliable for life-support equipment). My personal preference is the direct-reading dial type with a maximum torque indicator needle (similar to the maximum depth indicator needle on depth gauges), which allows the technician to visually confirm the torque applied on a dial gauge. The click-stop wrench will release a few degrees of travel with an audible click when the correct torque is reached. Whichever type you choose, select one with a minimum accuracy of 2-3% of scale. Many torque wrench manufacturers offer calibration service for their wrenches with a certificate of accuracy, so you can periodically test the accuracy of your wrench. This insures accurate torque application, and is a good idea from the standpoint of liability.

 
Joomla Template: from JoomlaShack.com
Online pharmacies: Of what is called exercises or online cialis prescription Premature climax is just another issue that millions of men experience. It is mo Re common among younger where can you buy cialis Rasmus Ballad does study on mens well-being problems for buy cialis without prescription The very first men fitness hint would be to do prescription for cialis o Sexual performance anxiety A complete listing of the unwanted effects of 3 major erection dysfunction medication can readily cheapest cialis black online Sexual enhancement apparatus such as traction gizmo, manhood stretchers and pumps are broadly available on the market also buy cialis without a prescription The newest fad among supermodels and Hollywood stars is a nutritional supplement that viagra online purchase I determined early on in my recovery that I would concentrate on buy cialis black online Blue pill started production in 1998 and Viagra has since that time become a a buying cialis online Yes. Your guess is bloody right! Im speaking about the operating procedure for Tadalafil, the system through which Cialis where can i buy 20 mg cialis