1. Compliance with SANS 10087-1 and SANS 329 Standards
Gas installation pipework in South Africa must adhere to the SANS 10087-1 standards for LPG systems and SANS 329, which deals with the materials and practices required for gas appliances and installations. These standards ensure the safety, durability, and efficiency of gas installations.
2. Materials for Gas Piping
- Copper and Steel: These are the most commonly used materials for gas piping, as they are durable, resistant to high pressure, and compatible with gas systems. The pipework must comply with SANS standards regarding thickness, corrosion resistance, and safety.
- Flexible Hoses: Only certified flexible hoses should be used for connecting gas appliances, such as stoves or heaters, to the fixed piping system. These hoses must be gas-approved and designed for LPG or natural gas use.
- Plastic Piping: In certain cases, high-density polyethylene (HDPE) is allowed for buried gas piping, but it must meet strict safety and corrosion resistance standards.
3. Pipe Sizing and Pressure Requirements
- Pipe Sizing: Proper pipe sizing is crucial to ensure the correct gas flow to all appliances. The pipe size is determined by factors such as the total gas load (BTU/hr), the length of the pipe run, and the allowable pressure drop. Incorrect pipe sizing can lead to insufficient gas supply or dangerous pressure levels.
- Pressure Regulation: Pressure regulators must be installed at key points to ensure that the gas flow is at the correct pressure for appliances. Low-pressure systems typically operate at 2.8 kPa for LPG, while high-pressure systems may require more stringent control.
4. Installation Depth and Protection for Buried Piping
- Depth Requirements: Gas pipes that are installed underground must be buried at a depth of at least 300 mm to protect them from physical damage, such as digging or construction.
- Protective Covering: If the pipework is metallic, it should be coated with a corrosion-resistant material, such as polyethylene, to protect it from moisture and soil contact.
- Tracer Wire: A tracer wire must be installed along with plastic pipes so that the buried gas line can be easily located in the future.
5. Routing of Gas Pipes
- Gas pipes should be routed in such a way that they are protected from accidental damage and are easily accessible for inspection and maintenance.
- Distance from Electrical Wiring: Gas pipes should be installed at least 150 mm away from any electrical wiring to prevent accidental sparks or interference.
- Support and Fixing: Piping should be properly supported along its length with brackets or other means to prevent sagging, which could cause pressure issues or damage.
6. Shut-off Valves and Safety Devices
- Main Shut-off Valve: A shut-off valve must be installed at the point where the gas enters the building, allowing for quick isolation of the gas supply in case of an emergency.
- Appliance Valves: Each gas appliance should have its own individual shut-off valve to allow for safe maintenance or emergency shutdown without affecting the entire system.
- Pressure Relief Valves: In high-pressure gas installations, pressure relief valves are required to protect the system from over-pressurization.
7. Ventilation and Combustion Air Supply
Gas pipes and appliances need to be installed in well-ventilated areas. Adequate ventilation prevents the build-up of gas in case of a leak and ensures that appliances have enough combustion air. Highlight the need for:
- Ventilated gas meter boxes.
- Proper air gaps around gas appliances.
8. Testing for Leaks and Pressure Integrity
- Leak Detection: Before a gas pipework system is put into operation, it must be thoroughly tested for leaks using either a pressure gauge or soapy water to detect any gas escaping from connections or joints.
- Pressure Testing: The entire pipework system should be pressure tested to ensure there are no leaks and that the system can handle the operational pressure of the gas supply.
9. Pipe Joints and Connections
- Approved Fittings: All pipe joints and connections must use approved fittings, such as compression fittings for copper pipes or welded connections for steel pipes.
- Threaded Connections: For threaded pipe connections, only approved jointing compounds or PTFE tape should be used to ensure a gas-tight seal.
10. Inspection and Maintenance
- Regular Inspections: All gas installations should undergo regular inspections by a certified gas installer to ensure ongoing safety and compliance with regulations.
- Maintenance: Any maintenance or repairs must be done by a registered gas installer, and any changes to the pipework should be tested for leaks and pressure integrity.
11. Gas Certificate of Compliance (COC)
- Once the pipework installation is complete, a registered gas installer must issue a Gas Certificate of Compliance (COC). This certificate is a legal requirement and confirms that the installation complies with all relevant safety standards.
Conclusion: Safety and Compliance First
Ensure that gas pipework installations comply with national safety standards to avoid any risks associated with gas leaks, fire hazards, or system failures. Only work with certified gas professionals to guarantee compliance.