|Better Farming Series 31. Biogas: What it is; How it is Made; How to Use it (FAO Better Farming Series, 1984)|
|How to build a small biogas unit|
49. Now you are ready to test the small drum for leaks. To hold
gas it must be airtight.
50. To check for leaks, close the valve or if you have no valve clamp or tie the gas line tightly as you were told in item 48.
51. Turn the small drum over and place it above the ground on stones or pieces of wood, but be careful not to damage the gas outlet or the valve or to loosen the clamp or the cord on the gas line. Now fill the small drum with water.
52. If you see water leaking from the drum, the gas outlet, the valve or the tied gas line, mark the place of each leak. Then empty out the water, being careful not to damage the gas outlet, and let the drum dry.
53. Seal the leaks by coating them with tar, mastic or paint on the inside and the outside of the drum.
54. If there are leaks around the gas outlet or valve, tighten the outlet or valve again and coat the joints with tar, mastic or paint.
55. When the sealing is dry, fill the drum with water again to be sure that the leaks are well sealed. If water still leaks, start over again.
56. When the small drum is well sealed and no longer leaks, your biogas unit is ready to use.
57. It is very important to seal all leaks carefully.