The specialty (high purity gas) industry has typically used “Specialty Gas Valves” that are Diaphragm Packless design. The diaphragm packless design has a proven leak-tight seal, low operating torque design ensuring ease of operation during filling and use. The low pressure liquefied gas valves for commercial grade "odorized" propane, butane and fuel-gas applications typically have nylon seat insert and controlled stem travel to assure positive shut-off. The diaphragm packless design is a much better design and much less likely to experience a leak from the valve.
Most of the high-purity hydrocarbons suppliers initially entered the market using only the diaphragm design valve. Remember, the high purity hydrocarbons are odorless
and do not contain an odorant. In the unlikely event of a leak, the diaphragm design adds that extra level of safety. The diaphragm design valve for high-purity hydrocarbons
do not have a bleeder port for allowing fill gauging to proper volume
typically observed in industrial grade LPG (odorized) LPG valves.
The high purity hydrocarbons fill process is completed by weight of each gas component (single gas, 2 component mix, 3 component mix, etc.) Absence of bleeder port eliminates another potential leak path or accidental discharge of odorless flammable gas.
We only fill products with diaphragm Packless design valves.