ADJUSTABLE SPRINKLER HEAD RISER

摘要

An apparatus for lengthening an extendible pipe comprised of first (32) and second (82) pipe portions, a cylinder (30) comprised of a hollow tubular shell (34) having an end wall (36) and an open end. A piston (80) is received in slidable and sealable engagement with the cylinder (30) and is connected to the second pipe portion (82). The piston (80), the end wall (36), and the cylinder (30), form the chamber of the cylinder (74) that is physically isolated from the interior of the pipe (41). Introduction of a control fluid into the chamber (74) displaces the piston (80) relative to the cylinder (30) so as to lengthen the pipe (32 and 82). The apparatus may be applied to a sprinkler head riser and burned as part of an in-ground sprinkler system.