Fixed length extension spindles are used when the distance between the valve and the ground surface is known so that only minor adjustment after installation is needed. The patented AVK fixed design facilitates fast and easy shortening of the extension spindle by use of a hacksaw.
Telescopic extension spindles are used when the distance between the valve and the ground surface can vary, and adjustment of the extension spindle may be required after installation. AVK telescopic extension spindles are designed with ears that can be fixed into AVK surface boxes and a lock spring that prevents the telescopic part from collapsing during installation.
AVK offers a wide variety of surface boxes. The floating surface boxes with internal fixation of telescopic extension spindles enable height adjustment after installation. The Classic range comprises both fixed and height adjustable synthetic surface boxes, all DVGW approved and withstanding traffic loads according to DIN 1072. The Futura range of synthetic surface boxes features a slim design with fixed height, a locking clip that prevents the lid from being lifted off unintentionally, and 100 % corrosion-resistant synthetic lids. Furthermore, AVK offers different other designs in both ductile iron and synthetic materials, as well as support tiles for increased support surface in weak soils.