Abstract: An orbital welding apparatus comprising a modular weld head unit including a circular rotor carrying a welding electrode for rotation about an axis for welding abutting ends of tubular members positioned in alignment on the axis. A drive assembly for driving the rotor includes a motor unit carried in a separate modular housing for ready manual connection and disconnection from the weld head unit. In the preferred form a transmission module is connected with the motor unit and connects to the weld head unit by a flexible drive shaft assembly to allow the motor unit to have substantially any desired orientation relative to the weld head unit. There is also disclosed a separate clamping assembly for holding the tubular members relative to the weld head unit.

Abstract: A check valve responsive to low cracking pressures includes first and second body portions defining a valve chamber. An inlet and outlet passage communicate with the valve chamber while a valve element received therein moves between open and closed positions responsive to pressure differentials. A stop member welded to the valve body is adapted to limit the opening movement of the valve element. An axially raised central portion of the stop member abuttingly engages the valve element to limit its opening movement yet permit fluid flow around the valve element to plural openings defined in a peripheral region of the stop member. A guide member is interposed between the stop member and valve element to urge a seal member disposed on one face of the valve element toward a seated, closed position.

Abstract: A check valve responsive to low cracking pressures includes first and second body portions defining a valve chamber. An inlet and outlet passage communicate with the valve chamber while a valve element received therein moves between open and closed positions responsive to pressure differentials. A stop member welded to the valve body is adapted to limit the opening movement of the valve element. An axially raised central portion of the stop member abuttingly engages the valve element to limit its opening movement yet permit fluid flow around the valve element to plural openings defined in a peripheral region of the stop member. A guide member is interposed between the stop member and valve element to urge a seal member disposed on one face of the valve element toward a seated, closed position.

Abstract: An inflatable valve member includes a valve body received in a fluid line and defining a generally annular flow passage therewith. A flexible member disposed on the valve body is selectively inflated to open and close the flow passage. A filter is interposed between the valve body and flexible member. The filter prevents injection of the flexible member in a pre-cured state into an internal passage provided in the valve body. A bonding material is provided between the flexible member and the valve body to provide a secure mechanical engagement therebetween as the material is cured to a cross-linked polymer state. The bonding of the flexible member also eliminates crevices in the final assembled valve member. The fluid line also includes a linear portion at the outlet to facilitate drainage of the valve.

Abstract: A relief valve for low pressure operation includes a valve body having an enlarged cylindrical bore in alignment with an inlet port and defining a valve chamber. An outlet opens laterally from the valve chamber at a location spaced from the inlet port. An insert member is received in the bore and defines an axially facing raised seat circumferentially about the inlet port at a location closely adjacent the outlet port. A poppet valve with a truncated conical configuration and a maximum outer diameter only slightly less than the inner diameter of the enlarged bore is mounted for engaging the seat and blocking flow through the inlet. A biased stem extends into the valve chamber in axial alignment with the seat insert. The stem has a cylindrical end portion which is received in a cylindrical opening formed axially into the poppet valve on the end thereof opposite the seat insert.