Abstract: A pump device has an impeller rotatable in a pump space, a rotational shaft interconnecting a rotational drive source and the impeller, a rotational shaft casing having a bearing assembly and/or a seal assembly, a first blocking flow mechanism, having a discharge section for discharging a portion of a main delivery liquid introduced from the pump space as a first blocking flow, for preventing a second blocking flow containing fine particles produced by the bearing assembly and/or the seal assembly from being entrained into the main delivery liquid, and a second blocking flow mechanism for combining the second blocking flow with the first blocking flow and discharging the second blocking flow from the discharge section while preventing the first blocking flow from being introduced.

Abstract: The present invention is a sealing mechanism for fluid for preventing leakage of fluid from a portion of threads of two members 2, 3 that are connected to each other via the threads, at least one of the two members having a hole of circular cross section for accommodating the fluid formed therein. The sealing mechanism for fluid includes an receiving portion 24 formed in an inner periphery of the hole and having a diameter larger than a diameter of the hole and a desired axial length, and a tubular seal member 10 having an axial length longer than the axial length of the receiving portion, in which the two members and the tubular seal member is made of the same kind of fluororesin, and when the two members are interconnected by engagement of the threads, the tubular seal member is axially compressed and deformed by at least 5% or more.

Abstract: A positive displacement pump includes a deformable hollow member for delivering a subject liquid by a cycle of contraction and restoration of its volume, a casing which contains the hollow member, and a pressurizing device for supplying and evacuating a hydraulic liquid in an annular space between the casing and the hollow member. The supplying of hydraulic fluid causes the contraction of the hollow member, and the evacuating of the hydraulic fluid causes the restoration (expansion) of the hollow member. A guide structure contacts and deforms the outer circumferential portions of the hollow member as the hollow member continues to expand to determine an initial contraction position of the hollow member. That is, a particular direction of contraction of the hollow member is set by the guide structure. Drive means periodically vary the circumferential position of the guide means relative to the hollow member to vary the initial contraction position of the hollow member.

Abstract: The invention related to this application is: a method for folding back an opening end of resin pipe comprising following processes, (a) a process for mounting an annular body to a circumference of a pipe, (b) a process for inserting a conically protruded portion of a guiding portion including the conically protruded portion and a curved surface groove formed around this circumference to an opening end of the pipe and simultaneously advancing with rotating the guiding portion, and (c) a process for continuing the advancement with rotating the guiding portion whereby folding back the opening end of the pipe, and inserting the folded back pipe opening end to the circumference of the annular body; and an apparatus for folding back an opening end of resin pipe comprising a clamping element for holding the pipe and a bending element and the clamping element including a tightening mechanism for pushing the pipe to radial direction, and the bending element including a guiding portion for advancing by rotating with a

Abstract: A connecting structure of resinous double pipes, having an external pipe and an internal pipe coated on an inner surface of the external pipe. The connecting structure comprises respective ends of opposite two external pipes; respective U-shaped ends of opposite two internal pipes; a clamping member for sealing and fixing a side of the U-shaped end enclosing the end of the external pipe; a joint ring disposed between respective ends of two double pipes opposite each other, having the same outer diameter as the external pipe; a joint socket mounted on an outer surface of a pair of the double pipes jointed by the joint ring; a bead retaining gap formed between an inner surface of the joint socket and the clamping member; and a gasket disposed between a bottom of the U-shaped internal pipe and the end of the external pipe.

Abstract: The present invention provides a pump which is capable of supplying a liquid free from worn materials and other impurities resulting from pump operation. In one embodiment, the pump includes a diverting passageway for diverting flow liquid from the main discharge opening to a gap between a cylinder and a shaft, between an impeller and a bearing and also includes a passageway for discharging the diverted flow liquid containing the worn materials from the gap during operation of the pump in which the main flow liquid is suctioned into the cavity of the pump and discharged through a main discharge opening.

Abstract: A plunger pump comprises a cylinder (1); a plunger (2) reciprocating within said cylinder; a sucking chamber (1a) formed upon a top of said plunger; a sucking pipe (4) and a discharge pipe (5) communicated with said sucking chamber; and slidable means (1b) formed upon an inner wall of said cylinder in the proximity of an open end thereof. The sucking chamber and the slidable means are intercepted from each other by an intercepting fluid stream formed therebetween, thereby any contaminants occurring from the slidable means are prevented from being penetrated into the sucking chamber, and discharged outside the plunger pump together with the intercepting fluid stream.

Abstract: A cartridge filter comprises a pleat-type porous membrane having a longer length than an effective filtering surface thereof; upper and lower end plates; a plurality of segmented cylindrical core members disposed between the upper and lower end plates; and protective caps for fastening and sealing an upper and lower reminder of the pleat-type porous membrane other than the effective filtering surface thereof. Each of said end plates is provided with a plurality of fins, each of which is covered by the pleat-type porous membrane. The pleat-type porous membrane is folded at each corner of respective end plates and fastened firmly between the end plate and the protective cap by melting means, adhesion or sealing means.