Abstract: A check valve between two pipe segments including a valve body and a valve housing. The valve body includes a valve opening through one face with a valve seat therearound, and a wall extending between the faces defining a part of the circumference of the fluid line between the pipe segment ends with a radial opening in the other part of the fluid line circumference having no wall. The valve housing is removably securable over the radial opening whereby the valve body wall and the valve housing together define a closed circumference of the fluid line between the pipe segments. A valve flapper is secured to the valve housing and pivotally biased relative to the valve housing toward closing against the valve seat, whereby the valve flapper is removable through the valve body radial opening when the valve housing is removed from the valve body.

Abstract: A grit removal unit including an influent channel directing wastewater with grit into a round grit removal chamber and an effluent channel receives wastewater output from the chamber. A divider wall extends upwardly between the sides of the influent channel, and gates at the upstream end of the divider wall are adjustable to selectively open channel portions on opposite sides of the divider wall. An output guide member is mounted to allow selective adjustment of output flow opening width “c” to the effluent channel. The output guide member has a horizontal bottom extending from the chamber into the effluent channel across the width of the output opening, and a guide wall extending upwardly from the guide member bottom. The guide wall has a forward end spaced from the chamber annular vertical wall to define the output flow opening width therebetween.

Abstract: A grit removal unit including an influent channel directing wastewater with grit into a round grit removal chamber and an effluent channel receives wastewater output from the chamber. A divider wall extends upwardly between the sides of the influent channel, and gates at the upstream end of the divider wall are adjustable to selectively open channel portions on opposite sides of the divider wall. An output guide member is mounted to allow selective adjustment of output flow opening width “c” to the effluent channel. The output guide member has a horizontal bottom extending from the chamber into the effluent channel across the width of the output opening, and a guide wall extending upwardly from the guide member bottom. The guide wall has a forward end spaced from the chamber annular vertical wall to define the output flow opening width therebetween.

Abstract: A grit removal unit including an influent channel directing wastewater with grit into a round grit removal chamber and an effluent channel receives wastewater output from the chamber. A divider wall extends upwardly between the sides of the influent channel, and gates at the upstream end of the divider wall are adjustable to selectively open channel portions on opposite sides of the divider wall. An output guide member is mounted to allow selective adjustment of output flow opening width “c” to the effluent channel. The output guide member has a horizontal bottom extending from the chamber into the effluent channel across the width of the output opening, and a guide wall extending upwardly from the guide member bottom. The guide wall has a forward end spaced from the chamber annular vertical wall to define the output flow opening width therebetween.

Abstract: A grit removal unit including an influent channel directing wastewater with grit into a round grit removal chamber and an effluent channel receives wastewater output from the chamber. A divider wall extends upwardly between the sides of the influent channel, and gates at the upstream end of the divider wall are adjustable to selectively open channel portions on opposite sides of the divider wall. An output guide member is mounted to allow selective adjustment of output flow opening width “c” to the effluent channel. The output guide member has a horizontal bottom extending from the chamber into the effluent channel across the width of the output opening, and a guide wall extending upwardly from the guide member bottom. The guide wall has a forward end spaced from the chamber annular vertical wall to define the output flow opening width therebetween.

Abstract: A check valve between two pipe segments including a valve body and a valve housing. The valve body includes a valve opening through one face with a valve seat therearound, and a wall extending between the faces defining a part of the circumference of the fluid line between the pipe segment ends with a radial opening in the other part of the fluid line circumference having no wall. The valve housing is removably securable over the radial opening whereby the valve body wall and the valve housing together define a closed circumference of the fluid line between the pipe segments. A valve flapper is secured to the valve housing and pivotally biased relative to the valve housing toward closing against the valve seat, whereby the valve flapper is removable through the valve body radial opening when the valve housing is removed from the valve body.

Abstract: An apparatus for introducing gas into a large body of liquid, including a horizontal frame on ballast adjustable floats, a pressurized gas source, a vertical shaft rotatable about its axis, and a plurality of blades submerged in the liquid and extending radially from a hub on the lower end of the shaft. The blades each have an elastomeric membrane around a longitudinal member, where the longitudinal member is hollow with a closed end and in communication with the pressurized gas source through the shaft on the other end, with openings through its lower side, and the elastomeric membrane has perforations which are spaced from the longitudinal member openings. A drive on the platform rotates the shaft via a ring gear around the shaft with a key connection thereto allowing axial movement therethrough, and an inwardly facing surface supported on bearings. A selectively driven and smaller pinion gear directly engages the ring gear.

Abstract: An apparatus for introducing gas into a large body of liquid, including a horizontal frame on ballast adjustable floats, a pressurized gas source, a vertical shaft rotatable about its axis, and a plurality of blades submerged in the liquid and extending radially from a hub on the lower end of the shaft. The blades each have an elastomeric membrane around a longitudinal member, where the longitudinal member is hollow with a closed end and in communication with the pressurized gas source through the shaft on the other end, with openings through its lower side, and the elastomeric membrane has perforations which are spaced from the longitudinal member openings. A drive on the platform rotates the shaft via a ring gear around the shaft with a key connection thereto allowing axial movement therethrough, and an inwardly facing surface supported on bearings. A selectively driven and smaller pinion gear directly engages the ring gear.

Abstract: A cutting tool such as a tile saw is pivotally connected to a linear guide rod with a four-bar linkage. The linkage allows the cutting tool to be raised and lowered over a work table to facilitate plunge cutting. One link of the four-bar linkage is mounted over the linear guide rod in a fixed perpendicular relationship with the surface of the work table to ensure that the blade of the cutting tool is maintained in a similar perpendicular orientation throughout plunge cutting. This is achieved by adjusting the links of the four-bar linkage as a parallelogram linkage. A linear bearing is fitted between the fixed perpendicular link and the guide rod to allow the cutting tool and linkage to freely slide along an accurate linear cutting path.