Stretcher (furniture) Stretcher (furniture) A stretcher is a horizontal support element of a table, chair or other item of furniture; this structure is normally made of exposed wood and ties vertical elements of the piece together. There are numerous styles of the stretcher including circumferential, double and spindle design. This term is sometimes referred to as a stretcher beam. A very common pattern for chairs has each front leg connected to the back by the lateral stretchers, which in turn are connected by a medial stretcher. In the William and Mary period chi (from the Greek letter chi - Χ) stretchers were
Ball valve operation, this will cause the ball to float downstream slightly. This causes the seating mechanism to compress under the ball pressing against it. Furthermore, in some types, in the event of some force causing the seat mechanism to dissipate (such as extreme heat from fire outside the valve), the ball will float all the way to metal body which is designed to seal against the ball providing a somewhat failsafe design. Manually operated ball valves can be closed quickly and thus there is a danger of water hammer. Some ball valves are equipped with an actuator that may be pneumatically,