Pressure Test Valves
This is a great little feature which is found on lots of old pumps. You can check the pressure reached at any time by applying a gauge to this valve located on the pump body – without removing the hose from the tyre. I’ve never seen one on a modern rubbish pump! It is, of course, an alternative to the in-built circular pressure gauge that you find on some old pumps – for example the Wood Milne/British Goodrich type. But these in built gaugaes are often damaged over the years and the pressure est valve is a more robust alternative. Sometimes you also see a pressure test valve on the connector at the end of the hose – see section on connectors. But its often a fiddle to try and get a pressure gauge on this whilst attached to the tyre.
As an alternative to having pressure test valves in the body of the pump, some manufacturers included one of these in-line in the flexible hose that attaches the pump to the tyre. Here are a couple of pictures, one of an in-line valve taken out of a hose, and one of a valve in a hose.
Naturally, William Turner (Kismet) went a step further and included, in some of his pumps, a complete in-line pressure testing gauge. These are very rare and sought after, see picture below.