| 摘要 |
The pump, for liquid-containing fuel tank (2) in a portable heater, has a cylinder (7) mounted on the tank and contains a sliding piston-rod (8). A handle (9) is fixed to the rod end furthest from the tank. A piston (10) forms a seal in one direction only, dividing the cylinder into two chambers (12,13). The nearest chamber is connected to the tank, via a non-return valve (14), only allowing air to enter the tank. The other chamber is connected, unhindered, to atmosphere. The sealing effect of the piston allows air to flow past it, from the chamber, furthest from the tank, to the one nearest it. The passage (16), through the piston-rod, contains a second non-return valve (17), by which the chambers can be connected together. Above a predetermined pressure, this valve allows air discharge to atmosphere from the chamber (13) nearest the fuel tank (2), but prevents flow in the reverse direction.
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