GB2280243A

GB2280243A - Valve manifold

Info

Publication number: GB2280243A
Application number: GB9315165A
Authority: GB
Inventors: Mark Roderick Oliver
Original assignee: OLIVER VALVES Ltd
Current assignee: OLIVER VALVES Ltd
Priority date: 1993-07-22
Filing date: 1993-07-22
Publication date: 1995-01-25
Anticipated expiration: 2013-07-22
Also published as: GB9315165D0; GB2280243B

Abstract

A valve manifold comprising two T-ported ball valves 2, 3 enmeshed by gearing 4, 5 each connected to a respective spigot 8 of the valves 2, 3. Actuation of an actuator handle 7 turns a spigot 8 of a valve to turn both ball valves through 90 DEG simultaneously via the gearing 4, 5. The manifold can thus be calibrated, zeroed, closed and vented by one operation, cutting down substantially on the time and skill normally involved in calibrating manifolds. <IMAGE>

Description

A VALVE MANIFOLD The present invention relates to a valve manifold, particularly but not exclusively to a valve manifold having simultaneously actuable valve elements.

Valve manifolds may be used in conjunction with a differential pressure transmitter for measuring the rate of flow of a fluid in a pipeline by measuring the pressure drop across an apertured plate placed in the path of fluid flow.

Conventional valve manifolds for this purpose are typically formed of three or five needle valves, a five-valve manifold having two isolating valves positioned in respective inlet lines of the manifold (the inlet lines being connected to the pipeline either side of the apertured plate), two vent valves positioned in respective vent lines connected to respective inlet lines, and an equalising valve provided in a passageway interconnecting the vent lines and the inlet lines. A three-valve manifold is not provided with vent lines or vent valves. A differential pressure transmitter is provided across the inlet lines and has a diaphragm therein to measure the pressure difference in the lines. From this measurement and using the known size of the aperture in the plate, a value is obtained which gives the rate of fluid flow in the pipeline.

After a measurement has been made, the manifold must be reset by equalising the inlet pressures, hence calibrating the differential pressure transmitter to zero. This requires a trained instrument engineer to perform a calibration procedure. The calibration procedure firstly requires both isolating valves to be closed (to isolate the manifold from the process medium in the inlet lines). The equalising valve is then opened to equalise the pressures between the lines, allowing the differential pressure transmitter to be zeroed. The vent valves are then opened to allow venting of excess pressure from the manifold (in a three-valve manifold excess pressure remains in the lines, which can be dangerous if it is desired to change any of the components).When the calibration procedure is finished, the equalising and vent valves must be closed, and finally the isolating valves opened to allow further measurements to be taken.

The operation is complicated to undertake and must be carried out separately for each manifold, which can be a lengthy and time consuming process as many thousands of manifolds may be provided on an oil refinery or offshore platform, for example.

It is an object of the present invention to obviate or mitigate the above-mentioned disadvantages.

According a first aspect of the present invention there is provided a valve manifold comprising at least two passageways, and a valve element provided in each passageway, wherein the valve elements are interconnected such that actuation of one valve element causes simultaneous actuation of the other valve elements.

The valve elements are preferably ball valves, most preferably T-ported ball valves, the simultaneous actuation of which causes simultaneous equalising, venting and isolating of the manifold. The valve elements are preferably interconnected by means of a gear mechanism, which operates one valve element on actuation of the other. Preferably, the gear mechanism is provided on a section only of each valve element, which preferably extends approximately 900 around the valve element.

An actuating handle is preferably provided on one of the valve elements, which actuating handle operates both valve elements by means of the gear mechanism. Alternatively, an actuator may be provided on one of the valve elements for remote or automatic actuation of the valve elements.

The actuation of the valve elements preferably calibrates and vents the manifold in one operation.

The valve manifold is operated by turning the actuating handle through 900, which isolates the process, zeros, vents and calibrates the instrument in one step. The time taken in calibrating the manifold is also greatly reduced compared to conventional manifolds. Further, the calibration step may be carried out automatically or by an unskilled operator.

According to a second aspect of the present invention there is provided a valve manifold comprising an inlet passageway connected to a vent passageway, wherein a T-ported ball valve is provided at the junction between the inlet passageway and the vent passageway.

A specific embodiment of the present invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of a manifold according to the present invention; Figure 2 is a sectional view of the illustrated manifold; Figure 3 is a diagrammatic representation of the manifold in the open position; and Figure 4 is a diagrammatic representation of the manifold in the closed position.

Referring to the drawings, there is illustrated a valve manifold 1 comprising two T-ported ball valves 2,3 each connected to a gearing section 4,5 which extend around approximately 900 of the axis of rotation of the ball valves. The gearing sections 4,5 are enmeshed, thus interconnecting ball valves 2 and 3.

The ball valves are formed of stainless steel and are encapsulated in a PTFE seat 6. Ball valve 2 is provided with a recess 7, into which locates a spigot 8 rotatable by an actuator handle 9.

The gearing section 4 is connected to the actuator handle 9, and rotates therewith. Gearing section 5 is connected to a spigot (not shown) provided on ball valve 3 and is capable of rotating the ball valve 3.

The valve manifold further comprises two inlet bores 10,11 which lead from the process pipeline (not shown) to a differential pressure transmitter 12, each inlet bore having a vent bore 13 extending at right angles therefrom. The ball valves 2,3 are positioned in inlet bores 10,11 at the junction between the inlet bores and the vent bores.

In order to operate the manifold to allow a measurement of the pressure of fluid flowing in the process pipeline (not shown), one inlet bore 10 is connected upstream of an apertured plate placed within the pipeline, whilst inlet bore 11 is connected to the pipeline downstream of the plate. In the normal working position of the manifold, the bores are in the position shown in fig. 3. Fluid may flow through bores 10,11 to the differential pressure transmitter, which measures the pressure difference in bores 10,11. No fluid passes between the ball valves 2,3, as there is no connecting bore between them. The differential pressure transmitter gives a reading of the rate of fluid flow in the pipeline based on the pressure difference on either side of the apertured plate.

If it is desired to calibrate or zero the differential pressure transmitter, valve actuator 9 is rotated through 900, which brings the valves into the position shown in fig. 4.

The manifold is isolated from the process, because valve 2,3 shut the inlet bores 10,11 so that no fluid passes therethrough. Any fluid present in the manifold vents out to atmosphere via vent bores 13.

The pressure in the manifold lines and all parts of the differential pressure transmitter thus becomes equal (ie. atmospheric). It is thus not necessary to provide an equalising valve between the bores 10,11, as the pressure in the lines is equalised by the vent valves.

Once calibration of the manifold is completed, the actuator 9 is rotated back so that the valves are once again in the position shown in fig. 3.

The manifold functions in other respects like a conventional manifold, and may simply be substituted for a conventional manifold where desired. The manifold may be used in other applications apart from fluid flow rate measurements.

The turning of the actuator handle performs all the functions previously required to calibrate, zero, and vent the manifold, without the need for a trained operator to be present. Testing carried out hydrostatically on the manifold at 1200 PSI for 1 hours in both the open and the calibrating positions showed no leakage on the vent and outlet bores. Thus, the manifold is rugged and reliable, and also does not have as many moveable or vulnerable parts as conventional manifolds.

The illustrated manifold is provided with an actuator handle for manual operation, but may instead be provided with an actuator for automatic or remote operation.

Claims

1. A valve manifold comprising at least two passageways, and a valve element provided in each passageway, wherein the valve elements are interconnected such that actuation of one valve element causes simultaneous actuation of the other valve elements.

2. A valve manifold as claimed in claim 1, wherein the valve elements are ball valves.

3. A valve manifold as claimed in claim 2, wherein the ball valves are T-ported ball valves, the simultaneous actuation of the ball valves causing simultaneous equalising, venting and isolating of the manifold.

4. A valve manifold as claimed in any preceding claim, wherein the valve elements are interconnected by means of a gear mechanism.

5. A valve manifold as claimed in claim 4, wherein the gear mechanism is provided on a section only of each valve element.

6. A valve manifold as claimed in claim 5, wherein the gear mechanism extends approximately 900 around the valve element.

7. A valve manifold as claimed in any of claims 4 to 6, wherein an actuating handle is provided on one of the valve elements, which actuating handle operates both valve elements by means of the gear mechanism.

8. A valve manifold comprising an inlet passageway connected to a vent passageway, wherein a T-ported ball valve is provided at the junction between the inlet passageway and the vent passageway.

9. A valve manifold substantially as hereinbefore described, with reference to the accompanying drawings.