Elements of Brass Instrument Construction:  Stölzel Valves Piston Valves The piston valve consists of a cylindrical outer casing (a) and the piston (b) inside, which fits tightly within the outer casing. The valve loop (c), as well as the main tubing (d), are soldered to the outer casing. The piston is perforated with ports (e) that lead the air stream either straight through the main tubing or into the valve loop. The valve loop is disengaged or engaged by the up-and-down movement of the piston within the casing that aligns the ports either with the main tubing or the valve loop. Stölzel Valves This valve type was developed as early as 1814 by Heinrich Stölzel, after whom it is named. The main difference between the Stölzel valve and the Périnet and Berlin valves is that the main tubing enters the piston from below. Two different Stölzel valve models can be distinguished. In the "early model," the piston is guided and the spring is stopped by a horizontal screw, going through the outer casing. In the "later model," the spring is enclosed in a barrel; therefore, no screw is visible at the valve casing. Guidance is provided by a key fitting in a groove or keyway at the valve casing. Click here to see an animation that shows how air flows through Stölzel valves (requires free Shockwave Player software to view). I. Early Model Stölzel Valve Parts of a piston valve (letters refer to diagrams at right and below): a = valve casing b = piston c = valve loop with slide d = main tubing f = touch piece, finger tip, lever g = valve stem h = top valve cap l = return spring q = spring barrel or capsule Early model Stölzel valve with horizontal guiding screw. Left valve: open.  Right valve: closed.  Valve at far right:  turned 90-degrees. II. Later Model Stölzel Valve Later Stölzel valve with spring inside capsule. Left valve: open. Right valve: closed. Return to Elements of Brass Construction National Music Museum The University of South Dakota 414 East Clark Street Vermillion, SD 57069 ©;National Music Museum, 2003-2007 Most recent update: October 23, 2007 This page was visited 30,400 times between April 1, 2003-September 19, 2007. You are the 1,034th visitor to this page since September 19, 2007. The University of South Dakota Return to Top of Page