A typical propane burner system consists of a fuel container (cylinder or tank) that is designed for a specific type of withdrawal (liquid or vapour), a main container valve and collar cap, pressure regulator, pressure gauge, burner shut-off valve, fuel line or hose and burner assembly (torch or kettle).
All assemblies involving propane gas must comply with standard CSA B149.1 Natural Gas and Propane installation code along with applicable provincial regulations.
Pressure Regulator and Pressure Gauge
The propane gas regulator is one of the most important parts of a propane gas system. The purpose of the regulator is to control the flow of gas and lower the pressure from the tank to the appliance(s) in the gas system. The regulator not only acts as a control regarding the flow and distribution of propane but also as a safety barrier between the high pressure of the tank and the torch or burner.
The type of pressure regulator used in a propane gas system depends upon the burner design. The burners in most asphalt kettles and tankers are designed for use with propane in liquid form (LPG).
Regulators for liquid service should be a type approved by ULC, ULI or CGA. They are usually adjustable to provide a 34.5 to 241.3 kPa (5 to 35 psi) delivery pressure, and must be connected directly to the gas container’s main valve outlet. A pressure gauge, a safety relief valve and a 6 mm (1/4 in) national pipe thread male x 14.3 mm (9/16 in) national fine male left-hand adapter are also usually provided on the downstream side of the pressure regulator.
A ULC, ULI or CGA approved vapour pressure regulator must be used with burners designed for use with propane in vapour form. Vapour regulators have the same features as liquid regulators except that a safety relief valve at the regulator is not normally provided since liquid gas is not likely to be present. A safety relief valve should be provided if there is any likelihood of liquid gas being present in a vapour system.
High Pressure LP Gas Regulators
High pressure LP Gas regulators, like all propane regulators stand between higher pressure on the inlet side and appliances or equipment requiring a lower pressure on the outlet side. Red propane regulators signify high pressure modulation. High pressure propane regulators used independently are servicing high demand equipment such as roofing kettles and torches. Certain high-pressure regulators are designed to work in either propane liquid or vapour withdrawal while others are designed to work in vapour withdrawal only. The propane delivery capacities of these high-pressure regulators satisfy BTU ratings up to 10,000,000 BTU/hr and even higher. This means that the usage can be in excess of 110 gallons per hour and supplying that amount of gas at a constant level requires high level pressure regulation. High pressure regulators vary in design, purpose and pressure delivery and just because the regulator is red doesn’t mean that it is suitable for any installation requiring high pressure regulation. Just like any other regulator, high pressure regulators are used in accordance with regulations and the manufacturers recommendations.
Adjustable High-Pressure Regulators
Propane flow pressure adjustment in high pressure propane systems is made possible by direct operated regulators, another name for adjustable high-pressure regulators. An adjustable regulator ensures that the required pressure is delivered to the equipment when the liquid level of the tank (or cylinder) is such that vaporization is not fast enough to meet the gas demands of the equipment. In other words, an adjustable regulator compensates for the lack of vaporization by allowing more pressure through the outlet and into the downstream gas line. Adjustable high-pressure regulators are commonly seen attached to tanks supplying roofing kettles and torches.
Regulators for liquid service should be a type approved by ULC, ULI or CGA. They are usually adjustable to provide a 34.5 to 241.3 kPa (5 to 35 psi) delivery pressure, and must be connected directly to the gas container’s main valve outlet. A pressure gauge, a safety relief valve and a 6 mm (1/4 in) national pipe thread male x 14.3 mm (9/16 in) national fine male left-hand adapter are also usually provided on the downstream side of the pressure regulator.