Steel injection grouting packers are designed for withstanding high pressure injection applications. With the tightening of the threaded shaft, compression of the rubber base takes place. This creates a compression seal within the drill hole. Steel is a strong material, and enables higher forces for tightening. The friction between the concrete substrate and expanded rubber sleeve is higher.
Low Pressure Zerk Fittings
Low pressure zerk fittings are similarly designed for lower pressure injections. In such cases, pumping or dispensing units limit the injection pressures.
A low pressure zerk will be equipped with a ball anti return valve which will be without a spring. With this, the pressure initially reduces for opening the valve, and the material enters the injection packer with a minimum resistance.
Application scope of injection packers
Injection packers are sometimes known as grouting nozzle. They find applications across a range of fields, including civil, industrial, municipal and tunnel construction, hydropower and water conservancy. The most important application of injection packers is in concrete chemical grouts field. It forms one of the most important components of high pressure chemical grouts technology.
Injection packers have an elaborate application scope for water plugging for concrete crack leakage, sewage treatment pool, subway and culvert. They may alternately be used for basements, underground garages and roof concrete plate cracks.
Epoxy injection packers are further useful for cracks in plates, columns, beams and concrete structures.
Working principle of injection packers
The grouting machine generates an incessant high pressure. This will inject chemicals into concrete cracks. It further squeezes out water entirely from the cracks, and fills up the cracks completely. This fulfills the purpose of stopping water.
Four prime classifications of injection packers based on the material are plastic, copper, aluminum and steel grouting injection packers. The latter three in this list are front stop type. This implies that the injection packers’ reverse valve is at the inlet. Similarly, the rear stop type has the feed port’s reverse valve at the outlet.
Packers are chosen based on specific conditions. In the case of front type packers, they are rotated down for relieving the drain and pressure. This is after the installation of the grouting nozzle. After the grouting finishes, they are screwed up.
But in the case of rear stop packers, draining and relieving pressure after installation is not possible. However, the grouting nozzle may be removed, to facilitate the next procedure after the construction completes.