초록 ▼

An improved method for transmitting fluid pressure signals through a conduit is disclosed wherein time delay is minimized. In the practice of this invention, a pressure pulse is applied to a conduit for a predetermined time interval and thereafter reduced to a maintenance level. The invention is par

An improved method for transmitting fluid pressure signals through a conduit is disclosed wherein time delay is minimized. In the practice of this invention, a pressure pulse is applied to a conduit for a predetermined time interval and thereafter reduced to a maintenance level. The invention is particularly useful in sequentially controlling subsea oil well valves from a remote surface station.

대표청구항 ▼

In a method for transmitting a pressure signal through a fluid-filled conduit by introducing to the conduit a step change in input pressure to yield a first of at least two step input pressure levels, wherein, after a distinct actuation time, the change in output pressure at a distance location in t

In a method for transmitting a pressure signal through a fluid-filled conduit by introducing to the conduit a step change in input pressure to yield a first of at least two step input pressure levels, wherein, after a distinct actuation time, the change in output pressure at a distance location in the conduit resulting from said step change in input pressure is equal to a percentage of said step change in input pressure and a first of at least two output pressure levels is thereby generated, the improvement comprising: (a) introducing to the conduit a pulse change in input pressure of a magnitude substantially greater than said step change in input pressure for a time period shorter than said actuation time, said greater magnitude and said shorter time period being chosen such that the output pressure at the distant location resulting from said pulse change in input pressure at no time reaches a second of said two output pressure levels; and (b) at the end of said shorter time period, changing the input pressure to the conduit to a maintenance level, said maintenance level being between said first output pressure level and said second output pressure level.