Special installation processes, not mentioned here, are used for toxic or high purity gases. Regulators and fittings are gas-type specific which limits interchange and adds safety. Unlike larger cylinders, lecture bottles all have identical valve threads, irrespective of the gas contained within.ĬOMMON LABORATORY GASES AND CGA REGULATOR FITTINGS This table lists standard CGA fittings for common laboratory gases COMMON LABORATORY GASESĬarbon dioxide (fitting requires flat washer) An auto ignition or explosion could result. Especially do not put oil or grease on the high-pressure side of a cylinder containing oxygen, chlorine, fluorine or another oxidizing agent. Never lubricate, modify, force, or tamper with cylinder valves. Do not use cheaters or adapters that circumvent the CGA fittings.Ĭompression fittings require no pipe sealants. Left hand fittings for fuel gases have a cut mark through the nut. This prevents accidental mixing of incompatible gases from an interchange of connections. Threads on cylinder-valve outlet connections have been standardized by the Compressed Gas Association for specific gas types.
Do not move a gas cylinder that may have been exposed to fire or excessive heat. Transport using a wheeled cylinder cart with the capped cylinder strapped to the cart. Empty cylinders shall be promptly removed. Never bleed cylinders completely empty leave a slight pressure to keep contaminants out. Promptly remove the regulator from an empty cylinder, replace the valve-protective cap, and label the cylinder by using an “empty” tag or writing on the side of the cylinder with chalk. When the cylinder is not in use, close the main cylinder valve tightly and add the protective valve-protection cap. Only cylinders that are in use shall be kept in the laboratory. Maximum allowable storage quantities vary depending on campus, building, floor, control area, fire rated design and type of gas. When transporting lecture bottles, use a cart and block the bottles to prevent rolling and falling.Whenever possible, purchase lecture bottles from suppliers who will accept the return of empty or partially empty bottles. If labels and valve tags do not agree, or if there is any question as to the contents of a lecture bottle, return the unused bottle to the supplier or contact Research Safety.Unlike larger cylinders, lecture bottles all have identical valve threads, irrespective of the gas contained within.Lecture bottles do not have pressure-relief devices to prevent rupturing or a transport cap.In addition to standard precautions, the following special rules apply to work with lecture bottles in the laboratory: Secure cylinders by metal channels, nylon bench straps or chains. Keep the cylinder valve-protection cap on when not in use. If the chain or belt is too low or too high, it will not hold the cylinder securely. Secure the cylinder above its center of gravity (~2/3 up the cylinder). Cylinders designed for liquid phase dispensing have a siphon, or “dip”, tube. Some gases, such as carbon dioxide, are commonly used in both a liquid and gas form. Acetylene is the only common dissolved gas. Dissolved gas cylinders are packed with an inert, porous filter saturated with the solvent which stabilizes the volatile gas. Dissolved gases are dissolved in a liquid phase solvent.The standard 5 foot gas cylinders supplied by gas vendors at a pressure of 2,200 – 2,400psi, contain an average of 250 cubic feet of gas at normal temperature. Examples: argon, oxygen, nitrogen, hydrogen. Non-liquefied gases are entirely gaseous at normal temperatures regardless of charge pressure.Examples: chlorine, propane, nitrous oxide.
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