Valves are normally bolted to a headwall structure, with spigots extending into the wall. For complete drainage, the sill plate should be set level with the floor of the pond.
In the standard installation procedure described below, stainless steel chemical anchor
bolts are used, in
conjunction with a compressible gasket of bitumen-impregnated
|See below for Installation Procedure.|
View of gasket material, showing two methods of joining.
STANDARD INSTALLATION. Headwall structures should be smooth, and flat to within a tolerance of ±3mm per metre. Mounting cleats have oversize holes, to allow for the inaccuracies in masonry drilling. The valve may be positioned and used as a drilling jig.
Drill 14mm holes, to a depth of 110mm. Clean the holes and install the chemical anchors, in accordance with the instruction sheet supplied.
Glue strips of gasket material to the back face of the valve, as illustrated above, using the contact adhesive supplied. Note the two methods shown for joining gasket. It is necessary to scarf the joints as shown, either at 30°, or half checked, so that the joint faces come tightly together when compressed.
The gasket material, which is initially 50mm by 50mm square section, compresses, in use, to approximately 10mm, forming an excellent seal against concrete surfaces.
NOTE. To avoid distorting the valve when compressing the gasket, tension the bolts uniformly and use the slotted shims provided. Three shims will be under each cleat on a flat headwall, providing approximately 10mm for the compressed gasket. All cleats should be bolted down firmly against shims.
If the headwall is not flat, place the valve in position before attaching the gasket and check the number of shims required to just fill any gap at each cleat. Write this number on the cleat. When finally attaching the valve, use three shims, plus the extras noted for each location. Spare shims are provided in the kit.