Geograph - photograph every grid square

During the site warm up No. 4 boiler has reached 80 psi and lifted its safety valves. Testing the safety valves is part of every steaming weekend and also an important part of the annual inspection by an insurance company recognised inspector. No. 5 to the right is coming towards the end of a lengthy overhaul. The boilers have an annual inspection with a major inspection every 10 years. The latter requires the boilers to be stripped down and the flues opened to expose shell seams for inspection. No. 5 is about to enter its second ten year stint since the pumping station was preserved and No. 5 was first steamed in 1999.