The residual pressure inside the gas cylinder is taken away from the final result at full pressure .I had only 20 left. at full pressure, if it should be 200, then it means I have to patch for 180 at least.just at the price of 3250sum, they took only 50000sum from me until the required pressure was completely filled with methane.I'm happy.they work very conscientiously.alas , in the city of Tashkent , you will not even find such recalculations .