"Engineered Surfaces for Exceptional Performance"
"Engineered Surfaces for Exceptional Performance"

Article Index

Fuel

A supply of liquid propane (LPG, propylene, MAPP-gas) from cylinder or tank at pressure 100-120 PSI is required.

Typical Consumption of Fuel (Data for Propane) 

Gun

C-7/AK-07

C-6/AK-06

AK5/AK5-ID

AK4-ID

Gas Fuel Rate SLPM

120- 150

90- 100

60- 70

20- 30

Weight Consumption g/min

236- 295

177- 196

118- 138

39- 59


NOTE: During the gun ignition the gas flow is 1.5 times higher than during the gun operation. For liquid withdrawal, the fuel cylinder must have so called liquid withdrawal valve, equipped with the dip-tube. Connection for liquid withdrawal valve (CGA 555 in the USA – “male” thread on the valve) is different than for gas withdrawal valve (CGA 510 in the USA – “female” thread on the valve). 

Kermetico Supplies LPG Hose Assemblies, 15-feet each to connect:

  1. Cylinder to vaporizer (CGA 555 for liquid withdrawal to connect to cylinder, 1/4"NPT Female shutoff valve and 250 PSI hydro-static valve);
  2. Vaporizer to control console hose assembly

When using natural gas as a fuel, the inlet pressure of 110-140 PSI is required. Check needed consumption of the gas dependent on the gun type.

Fittings: 1/4"NPT x 3/8” JIC. Hose ID 3/8”.

Recommended Piping: Tube 3/8”OD x 0.305”ID

Pressure Buildup in the LPG Cylinder

Required minimum pressure of 100 PSI in the LPG cylinder is achieved when the cylinder temperature exceeds:

  • 11°C – for propylene.
  • 18°C – for propane.
  • 31°C – for propane-35…40% butane LPG mixture.
  • Over 44°C – for propane - 60% butane LPG mixture.

NOTE: The vaporizer does not increase the output gas pressure.

To reach/exceed needed 100 PSI pressure in the cylinder, 3 major methods can be used: 

  • Heating of the propane/LPG cylinder above mentioned critical temperature
  • Using the liquid fuel pump
  • Using the “nitrogen blanketing” approach

Heating of LPG cylinder

  • Heating of LPG cylinder is easily achieved with electrically heated blankets, rated for hazardous area locations. Kermetico offers Power-Blanket (240 W, 110 VAC or 240 VAC) with heating temperature preset to 38°C (accuracy +/-5°C), rated for Class 1, Group D, Div.1 hazardous area locations (propane service, continuous hazard). Dimensions meet 100 LBS. (45 kg) cylinder size. The 2 blankets are recommended per such cylinder.
  • Heating of LPG cylinders in hot-water bath is less convenient, but frequently used method for building the pressure in LPG cylinders. It has advantage over electrical heating when several cylinders are manifolded and heated simultaneously.
  • Heating above 42°C is considered unsafe for LPG according to many local LPG Codes. Thus, heating should be not the choice for LPG with 50% or higher content of butane. 

LPG Pump

By special order, Kermetico Inc. manufactures LPG pump station with differential pressure 80 PSI, maximum liquid flow 3 LPM (1.5 kg/min), powered with explosion-proof ¼ HP electrical motor (Class 1, Group C&D). The motor RPM setting is controlled by variable frequency drive.

Nitrogen Blanketing

The pressure in LPG cylinder is built up by adding compressed nitrogen into the gaseous phase of the cylinder. Beside liquid-withdrawal valve, the LPG cylinder (or tank) must have additional gas-withdrawal valve to connect to the source of regulated-pressure nitrogen.

Kermetico Inc. offers a nitrogen hose assembly for “Nitrogen Blanketing” setup. The assembly includes shutoff valve, check valve, flow-limiting valve and pop-off safety valve. The nitrogen hose is connected to the gas-withdrawal line of the LPG cylinder, while regulated pressure nitrogen is supplied to the hose from the nitrogen source (compressed nitrogen cylinder with regulator). Pre-set pressure on regulator creates the same pressure in the LPG cylinder through “nitrogen blanket”. The liquid fuel is supplied from the cylinder to vaporizer through the liquid-withdrawal valve at constant preset pressure.

Kermetico Inc. also offers Worthington 100-lbs. LPG cylinders, equipped with both liquid-withdrawal valve (dip-tube installed) and gas-withdrawal valve, as well as with filling up valve. The cylinders are rated to 290 PSI (test pressure 450 PSI).