Air & Hydraulic Systems has announced the availability of a complete range of lockable ball, butterfly and diaphragm valves, from Austrian Thermoplastic valve manufacturer, Praher Valves GmbH. All butterfly valves, diaphragm valves and “S4” type ball valves are now supplied complete with a locking mechanism at no extra charge. Praher’s patented locking mechanism permits the operator to select either the open or closed position of the valve and secure it in that position with the aid of a padlock or similar locking device. In the case of the butterfly and diaphragm valves, the hand lever/hand wheel may be locked in open, closed or a variety of increments in between. Praher ball, butterfly and diaphragm valves are also available with pneumatic or electric actuators, proportional controllers, and position indicator switches if required.