Existing pipe cut-off method, existing pipe slitting method, piping structure, and valve insertion method for inserting a valve in a line without stopping passage of water or fluid

A piping structure comprising:

• an existing pipe;
• a seal-up housing provided on said existing pipe for rotation relative to said existing pipe in a circumferential direction of said existing pipe to cut a groove in said existing pipe that extends approximately 180 degrees in the circumferential direction of said exiting pipe, said groove having a fixed groove width and roughly U-shaped end portions, said seal-up housing enclosing a part of said existing pipe in an airtight state via a set of seal members that contact said existing pipe about at least two outer circumferences of said existing pipe that are spaced apart in the longitudinal direction of said existing pipe, said seal-up housing having at least two split portions that receive said seal members, each split portion having a unitary construction that extends completely across said at least two outer, spaced apart circumferences of said existing pipe, thereby allowing said at least two split portions to move as a single unit around said existing pipe during a cutting operation;
• a sluice valve body provided in said seal-up housing and radially moveable through said groove of said existing pipe between an open position and a closed position, said sluice valve body having a rubber packing that contacts (1) an inner circumferential surface of said existing pipe and (2) a surface forming said groove in the closed position to stop a passage of fluid in said existing pipe;
• and
• a valve rod connected to said valve body to move said valve body in the radial direction.

An existing pipe slitting method, comprising the steps of:

• rotatably mounting a seal-up housing on an existing pipe, such that the seal-up housing encloses a part of the existing pipe in an air tight state via a set of seal members that contact the existing pipe about at least two outer circumferences of the existing pipe that are spaced apart in the longitudinal direction of the existing pipe, the seal-up housing having at least two split portions that receive the seal members, each split portion having a unitary construction that extends completely across the at least two outer, spaced apart circumferences of the existing pipe, thereby allowing the at least two split portions to move as a single unit around the existing pipe during a cutting operation;
• accommodating a cutting tool, which is supported for rotation about an axis that extends in a radial direction of the existing pipe and is provided with a plurality of blades, in the seal-up housing;
• and
• while rotating the cutting tool about the axis,
• (1) feeding the cutting tool in a radially inward direction of the existing pipe to slit the existing pipe, and
• (2) rotating the seal-up housing including the at least two split portions together with the cutting tool in a circumferential direction of the existing pipe to slit the existing pipe in a range of approximately 180 degrees in the circumferential direction.

A piping structure comprising:

• an existing pipe through which a fluid is flowing;
• a seal-up housing mounted on said existing pipe and sealing up said existing pipe in an airtight state via a set of seal members that contact said existing pipe about at least two outer circumferences of said existing pipe that are spaced apart in the longitudinal direction of said existing pipe, said seal-up housing having at least two split portions that receive said seal members, each split portion having a unitary construction that extends completely across said at least two outer, spaced apart circumferences of said existing pipe, thereby allowing said at least two split portions to move as a single unit around said existing pipe during a cutting operation, said seal-up housing rotatable relative to said existing pipe in a circumferential direction of said existing pipe;
• a cutting tool mounted in said seal-up housing (1) for rotation about an axis that extends in a radial direction of said existing pipe and (2) for translation in the radial direction relative to said seal-up housing to cut said existing pipe;
• wherein said seal-up housing including said at least two split portions and said cutting tool are rotatable together in the circumferential direction of said existing pipe so that when (1) said cutting tool is rotated about said axis and (2) positioned radially inward to cut said existing pipe, said cutting tool slits a top portion of said existing pipe to provide a groove extending approximately 180 degrees in the circumferential direction of said existing pipe.

An existing pipe slitting method, comprising the steps of:

• rotatably mounting a seal-up housing on an existing pipe, such that the seal-up housing encloses a part of the existing pipe in an air tight state via a set of seal members that contact the existing pipe about at least two outer circumferences of the existing pipe that are spaced apart in the longitudinal direction of the existing pipe, the seal-up housing having at least two split portions that receive the seal members, each split portion having a unitary construction that extends completely across the at least two outer, spaced apart circumferences of the existing pipe, thereby allowing the at least two split portions to move as a single unit around the existing pipe during a cutting operation;
• providing a cutting tool in the seal-up housing, the cutting tool being supported for rotation about an axis that extends in a radial direction of the existing pipe;
• and
• while rotating the cutting tool about the axis,
• (1) feeding the cutting tool in a radially inward direction of the existing pipe to slit the existing pipe, and
• (2) rotating the seal-up housing including the at least two split portions together with the cutting tool in a circumferential direction of the existing pipe to slit a top portion of the existing pipe in a range of approximately 180 degrees in the circumferential direction.