Diaphragm valve assembling method, diaphragm valve assembly structure, and diaphragm valve

1. A diaphragm valve assembling method through which a twist of the diaphragm is prevented during assembly, the diaphragm valve assembling method comprising:

a step of inserting a bonnet, which pressurizes an outer periphery of a diaphragm, into a body having a valve seat provided to a valve chamber and the diaphragm being arranged thereabove;

a step of screwing a fastening nut into an opening of the body;

a step of fixing a rotation-stop jig inserted through a through hole of the fastening nut and the bonnet via fixing means; and

a step of fixing the body and the rotation-stop jig via paired fixing jigs and fastening the fastening nut, with the bonnet being in a non-rotational state, to tightly attach the bonnet to an outer seal part of the diaphragm.

2. The diaphragm valve assembling method according to claim 1 , wherein the body has a rectangular shape, and the body is inserted and fixed to a fixing groove of a similar shape formed on one fixing jig of the paired fixing jigs so as to be in a non-rotational state, and a notched step surface formed on an upper part of the rotation-stop jig is inserted and fixed to a groove-shaped engagement surface formed on another fixing jig of the paired fixing jigs so as to be in a non-rotational state.

3. The diaphragm valve assembling method according to claim 1 , wherein, with the paired fixing jigs fixed by a vise, an engaging part of the fastening nut is engaged by a tool to tightly attach the bonnet to the outer seal part of the diaphragm.

4. The diaphragm valve assembling method according to claim 1 , wherein the fixing means is configured by fixing lower portions of a plurality of pins to fixing parts formed in the bonnet and inserting upper portions of the plurality of pins into fixing holes of the rotation-stop jig to assemble the bonnet and the rotation-stop jig in a non-rotational state.

5. The diaphragm valve assembling method according to claim 4 , wherein the body has a rectangular shape, and the body is inserted and fixed to a fixing groove of a similar shape formed on one fixing jig of the paired fixing jigs so as to be in a non-rotational state, and a notched step surface formed on an upper part of the rotation-stop jig is inserted and fixed to a groove-shaped engagement surface formed on another fixing jig of the paired fixing jigs so as to be in a non-rotational state.

6. The diaphragm valve assembling method according to claim 4 , wherein, with the paired fixing jigs fixed by a vise, an engaging part of the fastening nut is engaged by a tool to tightly attach the bonnet to the outer seal part of the diaphragm.

7. The diaphragm valve assembling method according to claim 4 , wherein the fixing parts are equidistantly-bored fixing hole parts, and the plurality of pins are inserted in the equidistantly-bored fixing hole parts for fixing.

8. The diaphragm valve assembling method according to claim 7 , wherein the body has a rectangular shape, and the body is inserted and fixed to a fixing groove of a similar shape formed on one fixing jig of the paired fixing jigs so as to be in a non-rotational state, and a notched step surface formed on an upper part of the rotation-stop jig is inserted and fixed to a groove-shaped engagement surface formed on another fixing jig of the paired fixing jigs so as to be in a non-rotational state.

9. The diaphragm valve assembling method according to claim 7 , wherein, with the paired fixing jigs fixed by a vise, an engaging part of the fastening nut is engaged by a tool to tightly attach the bonnet to the outer seal part of the diaphragm.