Valves

A row of valves sits on top of the retort vessels at the Bathurst Gasworks, mounted into the off-take pipework that carried gas away from the carbonisation chambers below. The valves are heavy cast iron and brass, weathered to a uniform rust-brown across the working surfaces. Wheel handles rise from each valve body, sized to be turned under load. Pipework runs from valve to valve in tight bends, carrying the crude gas across the retort top to the down-runs that fed the condensers and purifier plant. Several gauges remain in place along the run. The brickwork behind the valves is darkened where heat and soot worked into the surface.

These valves controlled gas flow during the carbonisation process. As each retort came up to temperature and the volatile fraction started to come off, the gas off-take valve was opened to draw the gas away to the condenser. As the charge worked through, the operator on the retort floor adjusted the valves to balance the take across the chambers. Operations of this kind ran continuously at the Bathurst Gasworks from 1888 until 1979 under council coal-gas, and from 1979 until 1987 under AGL LPG reforming with the same off-take arrangement repurposed. The valves have not been worked in earnest since.