FR2674312A1 - Choking valve - Google Patents

Abstract

The invention consists in producing an extremely robust valve at any point on a tube, without cutting the tube, by introducing this valve through a small orifice. The device consists in installing, inside the tube (1) to be choked, a holding shaft (2) onto which a thin rope will be wound tangentially so as to constitute a ball (3) which very progressively closes off the tube. The system is particularly suited to repairs of damage to pipelines because it resists very high pressures, and can be fitted in an emergency. It may also be suitable for halting the flow on a sabotaged (botched) or accident-damaged oil well.

Description

CLOGGING VALVE
Sector concerned:
Petroleum and chemical industries, all industries using piping.

Aim of the invention:
The present invention relates to clogging at any point of a pipe with a type of 'valve' that can withstand very strong thrusts, (several tens of tonnes if necessary) by introducing the closure system by a set of small side holes.

State of the art:
Existing devices which consist in placing a closure system by a set of lateral holes of diameter much smaller than the diameter of the tube to be sealed have the disadvantage of producing a closure which does not withstand high pressures. (Problem of resistance of materials ).

The more robust systems require intervention by one end of the conduit or require cutting the tube at the valve which may be impossible in some cases.

The device of this invention overcomes these drawbacks and its manufacturing process and implementation remains simple.

Description of the invention:
The device consists in constructing a valve from outside the tube (1), to be plugged by passing through orifices for setting up a holding pin (2), and a small hole through which one will wind up tangential to the axis (by rotation of the axis), a rope, cable or other foil unwound from the outside and returning through this hole so as to constitute a ball (3) which obstructs the tube.

The only remaining problems (hooking a rope on an axis inside a tube and winding the sealing element) are known and simple techniques, positioning tools (4), screw fixing systems ( 5) and blocking pusher.

We will choose a method of hanging the cable on the axis by a tool adapted to the case to be treated. Note that the positioning tool can serve as a guide for winding the sealing element.

Any winding carried out along a tangent to the wound rope, and parallel to the longitudinal axis of the tube, has the advantage of touching the edge of the tube at the time when it is necessary to start an additional layer of the winding, this constitutes a precious guide for carrying out a sphere.

According to the coiled elements (steel cables, ropes, flexible pipes, fiberglass) an original valve is built with qualities which can be of enormous service in the event of unforeseen damage.

The contact points between the sealing system and the tube are not perfect and can cause leaks.

In the case of a vertical tube, it is easy to complete the seal by injecting a small light pipe (6) floating in the fluid which will rise to the highest point and plug any leaks between the sphere formed by the sealing system and the tube. one can also introduce small balls of density lower than the fluid or tennis balls for the large pipes under medium pressures.

These finishing elements can be introduced through the passage hole of the cable positioning system.

Variants: Depending on the case, use a steel cable, a rope, a Teflon-coated steel cable, a pipe, a steel tape to make up the winding. The steel strip of rectangular section is an interesting element in the presence of high pressures because the winding is more stable.

We can also combine several elements together for specific cases.

For other cases, it will be noted that the use of a pre-inflated pipe makes it possible, at the end of the ball, to put it under pressure compared to the fluid and to improve the tightness
We can, at the end of the race, finish with a flexible cord of small diameter to perfect the seal if we want to completely obstruct with a wired element.

Advantages of the device: - The elements used are simple and easy to make.

- The device allows a progressive obstruction of the conduit (no water hammer) - The device is very solid, its resistance depends only on the axis because the tube is sized to withstand the pressures to which it is subjected, so we know how to hold a thrust of several tens of tonnes with an axis adapted to the problem to be solved.

- The device produces a valve at any point of the tube, without recourse to intervention by one end.

- The device resists fire depending on the materials chosen - The device is suitable for all types of tubes (cylindrical or square sections.

- The device can be installed at any point on the circuit. (straight or angled section) - The device can be operated very gradually to obtain the desired flow.

- The device can be dismantled in a simple way (reverse from assembly) - The winding can be done at a significant distance from the tube by a control of rotation of the valve axis.

 - The assembly can be done with the pipe under pressure with a small loss of fluid during installation.

The only condition for making the device is to be able to drill the tube laterally along a diameter (axis) and a third small hole drilled at 90 degrees for the installation of the 'cable guide' tool.

5 Industrial application:
Installation of a tube clogging under pressure without accessing its end.

Installation of a valve on a damaged installation. This device can solve the problem posed by an eruptive oil well whose safety valves have been sabotaged or nonexistent.

This device solves the problems of flow stop in the pipeline at points not foreseen in advance, it can thus allow repairs.

Claims (4)

Claims:  1) Device characterized by the winding on one axis of one or more wire elements inside a duct, without cutting the latter, passing through small orifices in order to build a 'valve' or ball of obstruction, this from the outside and allowing to resist very strong thrusts.  2) Device according to claim (1) characterized by the establishment of a blockage for supporting a strong thrust.  3) Device according to claim (1) characterized by the use of a hose as a coiled element for achieving an almost complete and robust clogging by inflation of said hose.  4) Device according to claim (1) characterized by the use of an element or more wired elements of any section as wound elements and allowing to achieve a very robust clogging from outside the conduit.