Compressed, Liquefied & Flammable Propane Gas

Transcription

1 Compressed, Liquefied & Flammable Propane Gas 1. INTENT This Standard Operating Procedure (SOP) applies to all faculty, staff and students at Wilfrid Laurier University. It was developed by the EOHS office to outline safety precautions for the management and use of compressed and liquefied propane gas. Any questions regarding this SOP can be directed to the EOHS office at extension DEFINITIONS Compressed Gas Any material or mixture in a container where the absolute pressure is greater than 40 psi at 20 C. Liquefied Gas A liquid with a boiling point at atmospheric pressure that range from -90 C to -1 C (- 130 F to-1 F). Propane has a boiling point of C (-43 F) Flammable Liquid Any liquid having a flashpoint below 37.8 C (100 F) and having a vapour pressure not more than kpa (absolute) at 37.8 C as determined by ASTMD 323, Vapour Pressure of Petroleum Products (Reid Method). Taken from the Ontario Fire Code. Flashpoint The minimum temperature at which a liquid within a container gives off vapour in sufficient concentration to form an ignitable mixture with air near the surface of the liquid. Taken from the Ontario Fire Code. Propane has a flashpoint of -104 C (-155 F) 3. GENERAL GUIDELINES Compressed Gases Compressed gases are inherently hazardous due to the high pressure inside the cylinders. Knocking over an unsecured, uncapped cylinder of compressed gas can break the cylinder valve and result in a rapid escape of high-pressure gas that can transform a cylinder into an uncontrollable rocket or pinwheel, causing serious injury Page 1 of 8

2 and damage. Always keep cylinders secured both while in use and in storage. Compressed gases may also have flammable, oxidizing, dangerously reactive, corrosive or toxic properties. Propane gas can displace air, reducing oxygen levels in poorly ventilated or restricted areas and cause asphyxiation. Liquefied Gases Liquid propane is very cold. Contact between escaping compressed liquids and exposed skin can produce frostbite or a painful burn. Direct contact with the eye can cause damage or loss of vision. Always wear proper personal protective equipment including gloves and safety goggles whenever handling compressed liquids. Flammable Gases Propane is a highly flammable gas. It forms explosive mixtures with air and oxidizing agents. It forms hazardous combustion products. These are carbon oxides (CO, CO2). The Ontario Fire Code designates it a Class 1A liquid. This is the most flammable rating group. 4. PROCEDURES 4.1 Training Propane barbeque (BBQ) operators shall be under the direct supervision of a trained, competent supervisor. Supervisors who have staff that operate propane barbeques shall take and pass the WebCT course on Compressed Gas. Registration for this course can be arranged by contacting the Biosafety/ Chemical/ Radiation Officer in the Environmental/ Occupational Health and Safety Office (ext. 3108). The supervisor is deemed to be the trained and competent person for the safe handling and use of propane BBQs. Propane BBQ operators shall be trained by the supervisor in the safe use of the propane BBQ. (see 4.3) 4.2 Transportation between Event and Storage Areas When cylinders are being transported, valves must be closed and a protective cap must be attached, even if the cylinder is empty. Never keep a filled propane cylinder inside a hot vehicle. When transporting, secure the cylinder in an upright position so it will not fall, tip, shift or roll. Never transport cylinders inside a closed trunk; keep the trunk door partially open. If transporting within the passenger compartment of a vehicle, leave the windows open. Page 2 of 8

3 Always proceed directly to your destination and immediately remove the cylinder from your vehicle. 4.3 Handling Consult your departmental Material Safety Data Sheet before use. As with all chemicals, be sure to understand the properties of the gas before commencing work. To use a cylinder that is attached to a BBQ appliance: o Ensure the pressure regulating valve is not damaged. o Ensure all burner controls are in the OFF position. o Ensure that BBQ lid is open. o Open the cylinder valve slowly. o The ignition source should be lit before opening (to the ignite position) the burner control for the burner that you wish to ignite. o If the burner fails to ignite promptly, close the burner control immediately and wait five minutes before trying to ignite the burner again. To shut off the gas: o Close the cylinder valve. o Allow all gas in supply line to burn off. Once the burner has extinguished, turn the burner controls to the OFF position. Never bleed a cylinder completely empty; leave a residual pressure of at least 25 psi to prevent contamination gases from returning to the cylinder. Never expose skin or clothing to compressed gas flow as high velocity gas could penetrate the skin and cause serious injury. Refilling the cylinders by anyone other than the supplier is strictly prohibited. 4.4 Setup and Installation Fittings do not need to be lubricated. Oil and grease should never come into contact with attachments or cylinders. Never use Teflon tape on fittings as the tape may become lodged in the piping and cause a blockage. Read the label on the cylinder before connecting a new cylinder of compressed gas. If the label is illegible or missing, return the cylinder to the supplier. Never use a cylinder with unidentified contents. If a gas cylinder valve is damaged do not attempt to use the cylinder as the contents can exit with great force. Cylinders propelled by their contents may penetrate cinder block walls. Cylinders should be affixed to a permanent bracket on the BBQ during use. 4.4a Check for Leaks Page 3 of 8

4 Propane smells like rotten eggs or a dead skunk or animal. Propane manufacturers add this smell (Ethyl Mercaptan) to help alert customers to propane leaks Before using a propane appliance, particularly if you have just connected a cylinder, check for leaks using the following method. 1. Prepare a dish soap and water solution. 2. Turn the cylinder valve on (i.e., left or counter-clockwise); the appliance to which it is attached should be in the off position. 3. Spread the soap and water solution over the hose and the connections with a paint brush (or from a spray bottle). 4. Watch for bubbles forming in the solution. 5. If bubbles form, indicating a leak, shut off the cylinder valve. 6. If it is just a loose connection, tighten. 7. Repeat steps If leaking persists, tag the appliance and have it repaired by a qualified technician. 9. Never go over connections looking for leaks with a lighted match, cigarette lighter, or other flame. If there is a strong persistent smell of gas 1. Immediately put out all smoking materials and other open flames. 2. If you are able to, safely turn off the cylinder valve. To close the valve, turn it to the right (clockwise). 3. Immediately leave the area, restrict access, and call and Do not use the appliance until a qualified service technician has inspected your cylinder and appliance. 4.4b Regulator Safety A regulator is located between the cylinder and the hose connection to the appliance. The regulator reduces the gas pressure from the cylinder and maintains a constant pressure delivery to the appliance. A regulator should always be installed with its vent opening pointing downward. If this is not possible, cover the regulator with a proper cover to prevent the entry of rain, freezing snow or other liquids. The cover will also prevent the ice build up over the vent opening during the winter. A plugged regulator vent can cause excessive pressure resulting in high flames and explosions when the appliance is ignited or operating. Cylinder valve connections on regulators are designed to minimize the chances of using the wrong regulator. Verify that both the regulator and the line from the regulator to the BBQ elements are not damaged. Page 4 of 8

5 4.5 Storage Cylinders containing flammable materials shall be stored in a designated, non combustible outdoor enclosure. A lockable, wire mesh, two compartment cage is most appropriate. Signage indicating the nature and hazard of the gas being stored shall be located at the entry of the outdoor storage area, including a non-smoking sign. Full and empty cylinders must be segregated in the outdoor locations. Full and partially full cylinders shall be stored in the partition labelled Full Cylinders. Empty flammable gas cylinders are stored outside in the partition labelled Empty Cylinders. Keep only the anticipated number of cylinders in the location of the event. Extra cylinders should always be stored in a designated storage area away from the appliance and secured from tipping. Cylinders containing gases that may react with one another shall not be stored adjacent to one another (e.g., oxygen and propane). Nothing other than the gas cylinder is to be stored with the gas, particularly anything flammable or combustible. The cylinder connected to the BBQ must be secured in the appropriate bracket. Cylinders should not be stored near radiators or other heat sources. No part of a cylinder should be subjected to a temperature higher than 52 C (125.6 F). A flame should never be permitted to come in contact with any part of a compressed gas cylinder. Do not place cylinders where they may become part of an electric circuit. Keep cylinders upright. Never lay cylinders containing flammable gases on their sides. 4.5a Cylinder Labelling and Record Keeping All cylinders owned by a department or group on a university campus shall attach a colour designated tag to each of the cylinders in its inventory. The tag will be colour coded (figure 1) for each department. The information on the tag will, in addition to the appropriate colour, state the department name and the number assigned to the cylinder. Figure 1 Department Label Colour Athletics Yellow Food Services Red Student Sevices Residence Blue Student Union Green Brantford Orange A log book shall be located at the storage site (appendix 1). Page 5 of 8

6 When a cylinder is moved in or out of the designated storage area, a record of the date, your name, group name, cylinder number and hours of usage (if returning cylinder) will be made in the log book that is located in the cylinder storage area. 4.6 Replacement of Cylinders Label empty cylinders clearly with either EMPTY or MT and place a yellow ring (supplied in the storage area) around the top of the cylinder to indicate that it is empty. Move empty cylinders into the designated space in the storage area to await pickup or return to supplier. Leak testing of any connections that have been loosened or opened during replacement should be performed at the time of cylinder replacement. Leak testing of connections should be performed periodically while the cylinder is in use. The leak testing method is described in section 4.4a. 4.7 Emergency Situation Leaking Cylinder Propane gas must be treated with caution. If left to leak in a closed space, it may displace oxygen and create a risk of asphyxiation and/or explosion. A small release will produce a large volume of gas which will change the conditions of the ambient environment in a confined space very quickly. Residential use propane has a compression ratio of 1 to 270. A typical cylinder of liquid propane (18 litres) would expand to 170 cubic metres at normal atmospheric pressure. Most leaks occur at the valve in the top of the cylinder and may involve the valve threads, valve stem, valve outlet, or pressure relief devices. Do not attempt to repair leaking cylinders. If a large or uncontrollable leak occurs, evacuate the area immediately and call and extension Page 6 of 8

7 5. APPENDIX Relevant Standards Laboratory Health and Safety Manual, Laurier Environmental/Occupational Health & Safety Office, February REVISION HISTORY Revision Date Comments Initials 00 Oct 31/08 SOP comes into effect Page 7 of 8

8 Appendix 1: Propane Cylinder Sign-out Sheet Name (print clearly Group or Event Cylinder Number Number of Hours Used Date Out Date Returned