Abstract: A multiple walled metal chimney formed of a plurality of axially joined chimney sections each of which utilizes positionally captured spacer rings. Joint clamps are used to connect the chimney sections for formation of the complete chimney conduit. The spacer rings are positionally captured between annular shoulders formed in the inner and outer walls of the chimney sections to eliminate welding of the rings. The rings may include an expansion joint to allow circumferential expansion and contraction of the ring with the walls.

Abstract: In accordance with the present invention there is provided a device for use in servicing an oil well rod pump. The pump has a rod string with a rod clamp secured thereto above the polish rod. The device comprises an elongated, weight-supporting polish rod-receiving cylindrical sleeve. The inner diameter of the sleeve is greater than the diameter of the polish rod. A slot in the side of the sleeve extends along its length. The width of the slot is slightly greater than the diameter of the polish rod. A flange extends outwardly from each side of the slot. Releasable securing means extend between the flanges to secure the sleeve in position about the polish rod. The sleeve is to receive, resting thereon when in position about the polish rod, the rod clamp to permit servicing work on the pump above the rod clamp.