TECHNICAL DATA
Cylinder Storage and Use

Storage

Storage Area – Store gas cylinders in a ventilated and well-lit area away from combustible materials. Separate gases by type and store in assigned locations that can be readily identified. Store cylinders containing flammable gases separated from oxygen cylinders and other oxidants, by a fire-resistant wall (having a fire-resistance rating of at least a half-hour) or locate them at least 20 feet (6.1 meters) apart from each other. Poison, cryogenic and inert gases should be stored separately. Labels, decals or other cylinder content identification should not be obscured or removed from the gas cylinder. Cylinders should also be stored where they can be protected from tampering by unauthorized personnel.

Storage Area Conditions – Storage areas should be located away from sources of excess heat, open flame or ignition, and not located in closed or subsurface areas. The area should be dry, cool and well-ventilated. Use of a vent hood does not provide for a safe storage area except when a cylinder is actually in use. Outdoor storage should be above grade, dry and protected from the weather.

Securing Cylinders in Storage – The risk of a cylinder falling over and possibly shearing off its valve demands that a cylinder always be held in place with a chain or another type of fastener such as a bench or wall clamp. While in storage, cylinder valve protection caps MUST be firmly in place.

Cylinder Temperature Exposure – Cylinder temperature should not be permitted to exceed 125°F (52°C). Steel cylinders are typically used for more corrosive products. Though they are more durable than aluminum cylinders, they should not be stored near steam pipelines or exposed to direct sunlight. Aluminum cylinders are used for increased stability of mixtures containing certain components and they can be damaged by exposure to temperatures in excess of 350°F (177°C). These extremes weaken the cylinder walls and may result in a rupture. Do not apply any heating device that will heat any part of the cylinder above 125°F (52°C).

Empty Cylinders – Arrange the cylinder storage area so that old stock is used first. Empty cylinders should be stored separately and clearly identified. Return empty cylinders promptly. Some pressure should be left in a depleted cylinder to prevent air backflow that would allow moisture and contaminants to enter the cylinder.

Usage

Labeling – If a cylinder’s content is not clearly identified by proper labels, it should not be accepted for use.

Securing Cylinders Before Use – When a cylinder is in use, it must be secured with a fastener. Floor or wall brackets are ideal when a cylinder will not be moved. Portable bench brackets are recommended when a cylinder must be moved around. Stands are available for small cylinders, as well as for lecture bottles. Your Scott Representative can assist in determining which type of cylinder fastener best meets your needs.

Initiating Service of Cylinder – Secure the cylinder before removing the valve protection cap. Inspect the cylinder valve for damaged threads, dirt, oil or grease. Remove any dust or dirt with a clean cloth. If oil or grease is present on the valve of a cylinder that contains oxygen or another oxidant, do NOT attempt to use it. Such combustible substances in contact with an oxidant are explosive. Notify the nearest Scott facility of this condition and identify the cylinder to prevent usage.

Valve Outlet Connections and Fittings – Be sure all fittings and connection threads meet properly — never force. Dedicate your regulator to a single valve connection even if it is designed for different gases. NEVER cross-thread or use adapters between nonmating equipment and cylinders. Most cylinder valve outlet connections are designed with metal-to-metal seals; use washers only where indicated. Do not use Teflon® tape on the valve threads to help prevent leaking, it may become powdered and get caught on the regulator poppet causing full pressure downstream. Never use pipe dope on pipe threads. Also, never turn the threads the wrong way. This could produce brass particles that might get caught in the poppet.

Gas Cabinets – When hazardous specialty gases are used in an enclosed location, it is wise to provide an extra degree of protection for personnel. A gas cabinet can contain and vent leaking gas. A gas cabinet also accommodates manifolds and gas handling systems, providing an efficient and cost-effective means to safely organize specialty gas distribution equipment.

Cylinder storage problems are simplified because the cabinet/ manifold system concept encourages separation of gases according to their classification. For example, corrosives, oxidizers, flammables and toxics can be separated and grouped into separate cabinets. This satisfies both national and local fire and building codes.

In order to provide containment of potentially dangerous gases, cabinet exhaust systems should be designed with the capability to allow 150 to 200 linear feet (45.7 to 61 linear meters) per minute of air to pass through the cabinet with the access window open. This is equivalent to 13 air changes per minute. As an extra measure of fire protection, gas cabinets used to store flammables should be equipped with an integral sprinkler system. While exact requirements may vary with the specific application, a typical sprinkler would have a fuse rated at about 135°F (57°C) and a flow capability of approximately 40 GPM (2.524 L/s).

Consideration should be given to materials of construction when selecting a gas cabinet. For example, use of 11-gauge steel or better for the cabinet and door will ensure sturdiness and also provide a half-hour or more of fire protection. Horizontally and vertically adjustable cylinder brackets should also be specified to ensure that cylinders are properly secured. If poisonous gases are to be kept in the cabinet, an access window should be provided so the cylinder valves can be closed and leaks detected without opening the cabinet door and compromising the exhaust system. For cabinets used to store inert gases, a fixed window to allow visual inspection is an acceptable and economical alternative.

Terminating Service of Cylinder – Disconnect equipment from the cylinder when not in use for long periods and return the cylinder valve protection cap to the cylinder.

Transporting Cylinders – Always move cylinders by hand trucks or carts that are designed for this purpose. During transportation, cylinders should be properly secured to prevent them from falling or striking each other. Always use a cylinder cart equipped with a chain restraint. Do not move a cylinder with a regulator connected to it. Never transport a gas cylinder without its valve protection cap firmly in place. Keep both hands on the cylinder cart during transport. A cylinder cart or hand truck is not a suitable place for storage of a cylinder.