Abstract: A thermal type flowmeter comprising an elongated relatively small tubular probe, adapted to be inserted through a wall of a fluid containing vessel, contains an electrical resistance heater for heating the probe to a predetermined temperature. The electromotive force of a thermocouple, contained by the probe, indicates a voltage inversely related to the rate of heat dissipation from the probe to the surrounding fluid. With the temperature of the fluid being known or compensated for the rate of heat dissipation from the probe indicates the fluid flow rate.

Abstract: A gate valve having a flow passage therethrough is provided with a valve stem movable disc having an opening permitting fluid flow through the passageway when in register therewith and interrupting fluid flow when the disc is in a valve closed position. The disc is provided with a removable cylindrical plug mating with ring-like seats on opposite sides of the disc surrounding and coaxial with the flow passageway. Ratchet teeth on the plug engage a detent to rotate it through a predetermined arc each time the gate valve is closed.

Abstract: An elongated tubular housing, having inlet and outlet ports, forms a fluid passageway. A piston, loosely received by the inlet end portion of the housing, is coaxially connected with a throttle regulator comprising poppet type valves and a stem which extends through and seats the valves on respective end portions of a cage positioned in the outlet end portion of the housing. A spring, interposed between the piston and the cage, normally biases the valves toward an open position and acts to position the balanced valves at the respective end portions of the cage in response to constant fluid pressure drop across the piston.

Abstract: A generally horizontal container, interposed in a drilling mud conductor, forms an enlarged area passageway for the drilling mud. The container transversely journals a plurality of spaced rotating plate-like discs forming positive electrodes between negative electrodes formed by a plurality of spaced-apart interconnected panels with a peripheral portion of each disc immersed in the drilling mud. Solids in suspension are attracted by and deposited as a layer or film on opposing surfaces of the respective discs. A stationary scraper blade element, adjacent the discs, removes the deposited solids. Pressure operated plungers, disposed on opposing sides of the respective disc, periodically move the collected solids toward a discharge end portion of the scraper blade element for removal.