US 6,981,848 B1
Methanol injection system and method to prevent freezing of a natural gas pipeline
Kevin J. Cessac, Houston, Tex. (US)
Assigned to PGI International, Ltd., Houston, Tex. (US)
Filed on Feb. 29, 1996, as Appl. No. 8/609,973.
Int. Cl. F04B 49/02 (2006.01)
U.S. Cl. 417—14 19 Claims
OG exemplary drawing
 
1. A system for injecting an injection fluid into a pipeline at a remote location, the injection fluid being stored within a storage tank at the remote location, the system comprising:
an injection pump for injecting a selected amount of the injection fluid into the pipeline with each pump stroke;
a timer for sequencing stroke initiation of the injection pump at a selected time interval;
a control valve for controlling flow of pressurized fluid to power the injection pump;
a controller for controlling operation of the control valve;
an electric motor responsive to the controller for rotating a motor shaft and a cam rotated by the motor shaft;
a battery for powering the motor and the timer;
a sensor for initiating activation of the motor in response to a sensed pipeline condition; and the control valve operative in response to the rotational position of the cam to control opening and closing of the control valve.