Sluice valve installation method, and sluice valve installation structure used in sluice valve installation method

A sluice valve installation method of installing a sluice valve in a fluid pipe, the sluice valve being configured to open and close a flow passage of the fluid pipe in an uninterrupted flow state, the method comprising:

• a first step of attaching a housing of the sluice valve and a work valve configured to open and close a valve cover mounting opening portion of the housing to the fluid pipe;
• a second step of opening and closing the work valve to perforate the fluid pipe to form a through-hole through the valve cover mounting opening portion of the housing;
• and
• a third step of opening and closing the work valve to attach a valve cover incorporating a valve body to the housing to allow the valve body of the sluice valve to be inserted into the fluid pipe through the through-hole of the fluid pipe,
• wherein the third step comprises
• an insertion step of inserting a valve cover-side bayonet claw portion provided in the valve cover into a fitting groove portion provided in the valve cover mounting opening portion of the housing through a claw insertion portion provided in the valve cover mounting opening portion of the housing at a valve cover attachment/detachment position where the valve cover-side bayonet claw portion does not interfere with a housing-side bayonet claw portion corresponding to a part of the fitting groove portion thereby to insert the valve body of the valve cover into the valve cover mounting opening portion of the housing, and
• a rotation step of rotating the valve cover with respect to the housing with the valve cover-side bayonet claw portion being fitted into the fitting groove portion of the housing to cause the valve cover-side bayonet claw portion and the housing-side bayonet claw portion to be engaged with each other and retained in a valve body insertion direction.