Apparatus for determining the characteristic of a flowmeter
AssigneeCalibron Systems, Inc.
InventorsGary D. Cohrs, Edward E. Francisco, Jr.
Life of this patent
Estimating the term…
Abstract
A fluid flowmeter prover uses a measuring cylinder in series with a flowmeter to calibrate the flow meter. The cylinder has a piston which travels in synchronism with the fluid, the flow rate of which is to be measured. At the downstream end of the cylinder, a poppet valve connected to and within the piston opens to allow the fluid to pass through the piston. The poppet valve has a valve rod connected to a first coupling. A second coupling engages the first coupling and through a motor draws the valve and piston to the upstream end of the cylinder where they disengage, releasing the valve and allowing it to close for another run. The cycle repeats when the second coupling is driven down to reengage the first coupling.
Claims40
A flowmeter prover comprising:
- a fluid displacement measuring cylinder;
- a piston movable back and forth through the cylinder from an upstream position to a downstream position;
- a shaft assembly attached to the piston;
- a carriage movable back and forth from an upstream position to a downstream position;
- a grabber attached to the carriage, the grabber being releasably connectable to the shaft assembly;
- means for connecting the shaft assembly and grabber at the carriage's downstream position;
- means for disconnecting the shaft assembly and grabber at the carriage's upstream position;
- and
- means for driving the carriage back and forth to carry the piston from the piston's downstream position to the piston's upstream position through the shaft assembly.
A method of operating a flowmeter prover having a fluid displacement measuring cylinder connected in series with a flowmeter, a piston movable back and forth through the cylinder from an upstream position to a downstream position and a poppet valve permitting fluid flow from one side of the piston to the other side when open and blocking fluid flow from one side of the piston to the other when closed, the method comprising the steps of:
- pulling the piston with a carriage releasably connected to the piston from the downstream position to the upstream position when the poppet valve is open;
- releasing the piston at the upstream position and closing the poppet valve so that the piston moves toward the downstream position in synchronism with fluid flow through the cylinder;
- moving the carriage downstream to reconnect to the piston, the downstream carriage movement beginning before the piston reaches the piston's downstream position;
- and
- determining the fluid flow rate from the movement of the piston.
An apparatus for proving a flowmeter comprising:
- a fluid displacement measuring cylinder;
- a piston movable through the cylinder between an upstream and a downstream position;
- a movable rod connected to the piston extending axially through the cylinder to the cylinder's exterior;
- means for engaging the rod outside the cylinder;
- means for transporting the engaging means in an upstream direction to bring the piston from the downstream position to the upstream position, the engaging means engaging the rod as the piston is brought upstream and releasing the rod to allow the piston to travel downstream.
A method for operating a flowmeter prover having a fluid displacement measuring cylinder with an inlet near one end and an outlet near the other, a fluid displacement measuring piston adapted to travel through the cylinder between an upstream and a downstream position, and a valve which allows fluid to bypass the piston, the method comprising the steps of:
- placing the prover in a fluid line in series with a flowmeter under test;
- drawing the piston to the upstream position;
- closing the bypass valve so that fluid flowing through the cylinder drives the piston downstream in synchronism with the fluid flow through the fluid line;
- sensing the movement of the piston through the cylinder;
- opening the bypass valve;
- activating a chain drive mechanism;
- engaging a pusher bar on the chain drive mechanism with a guide plate connected to the piston;
- operating the chain drive mechanism to move the piston using the guide plate from its downstream position to its initial position;
- disengaging the pusher bar from the guide plate;
- and
- deactivating the chain drive mechanism.
A flowmeter prover comprising:
- an axially elongated flow measuring cylinder having an inlet and an outlet near its ends;
- a flow measuring piston moveable through the cylinder in synchronism with fluid flow;
- a shaft having a first end connected to the piston and having a second end lying outside the cylinder to travel along a prescribed path between an upstream position and a downstream position as the piston moves through the cylinder;
- a mechanical drive reciprocating between the upstream position and the downstream position of the second end of the shaft;
- and
- means connected to the mechanical drive for engaging the second end of the shaft near the downstream position to carry the piston toward the inlet and
- for disengaging the second end of the shaft from the mechanical drive near the upstream position to permit the piston to travel through the cylinder in synchronism with fluid flow.
Dependencies are inferred from the claim text.