US 7,080,658 B2Granted

Method for closing fluid passage, and water hammerless valve device and water hammerless closing device used in the method

AssigneesFujikin Incorporated, Tadahiro Ohmi

InventorsTadahiro Ohmi, Nobukazu Ikeda, Kouji Nishino, Masaaki Nagase, Kyousuke Dohi, Ryutaro Nishimura

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Abstract

A fluid passage is emergently-closed in a short time without causing a water hammer by an extremely simple device and operation. A water hammerless closing device includes an actuator operated valve provided in a fluid passage, an electro-pneumatic conversion device for supplying a 2-step actuator operating pressure Pa to an actuator operated-type valve, a vibration sensor removably secured to the pipe passage on the upstream side of the actuator operated-type valve, and a tuning box receiving a vibration detection signal Pr from the vibration sensor and delivering a control signal Sc to the electro-pneumatic conversion device for controlling the step operating pressure Ps′ of the 2-step actuator operating pressure Pa so that, with the control signal Sc being regulated, the electro-pneumatic conversion device outputs the 2-step actuator operating pressure Pa with the step operating pressure Ps′ capable of bringing the vibration detection signal Pr substantially to zero.

Claims3

Dependent claims

A water hammerless closing device comprising:

(a) a valve body;
(b) an actuator connected to drive the valve body;
(c) a vibration sensor removably secured to a pipe passage on an upstream side of the valve body;
(d) an electro-pneumatic conversion control device connected to receive input including a valve opening/closing command signal and the electro-pneumatic conversion control device operates to control an actuator operating pressure Pa inputted to the actuator by using a control signal Sc stored, in advance, in a data storage unit of the electro-pneumatic conversion control device;
and
(e) a computing control device having
a comparison computing circuit connected to receive input including a vibration detecting signal Pr originating from the vibration sensor, a step pressure setting signal Ps to be supplied to the actuator, a holding time setting signal Ts for maintaining the step pressure, and an allowable upper limit vibration setting signal Prm and the comparison computing circuit makes a comparison between the vibration detection signal Pr and the allowable upper limit vibration pressure setting signal Prm for modifying the step pressure setting signal Ps so the control signal Sc, composed of the holding time setting signal Ts and the modified step pressure setting signal Ps, are outputted to the data storage unit of the electro-pneumatic conversion control device.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/152,638Filed 15 Jun 2005 · continuation
Priority: JP 2002-36742019 Dec 2002
Published: US 2005/0241697 A13 Nov 2005
Granted: 25 Jul 2006
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

F16K 47/02
Means in valves for absorbing fluid energy: for preventing water-hammer or noise
F16K 47/023
For preventing water-hammer or noise: for preventing water-hammer, e.g. damping of the valve movement
F16L 55/043
Devices damping pulsations or vibrations in fluids: specially adapted for protecting instruments from water hammer or vibrations
Y10T 137/0324
Processes: with control of flow by a condition or characteristic of a fluid