The fineness of the Portland cement is tested by a specific surface area measuring instrument, and its specific surface area should be greater than 300 m2/kg, otherwise it is a non-conforming product. The national standard stipulates that the initial setting time of Portland cement is no earlier than 45 minutes, otherwise it is a non-conforming product; the final setting time is not later than 390 minutes, otherwise it is a non-conforming product. The volume stability of Portland cement must be qualified after inspection, otherwise it is a non-conforming product. Portland cement is divided into three strength grades according to the compressive strength of 3d and 28d, namely 42.5, 52.5, and 62.5. There are two types of each grade, normal type and early strength type (represented by R). Our range of bath taps and mixers are available in a gorgeous choice of designs. Choose from a range of contemporary or traditional Basin Taps or bath taps, or if you are looking for something a little more modern, select from our range of deck mounted or wall mounted basin and bath mixers which deliver water through a single spout. For the ultimate flexibility, also take a look at our range of bath shower mixers. Our bath taps and mixers combine exceptional quality design with real value for money. Selected products in the range also include clever flow limiting devices to help save water. Taps with lever handles have also been designed to be easy to use and some of our ranges are suitable for low pressure. Bathroom Basin Taps, Bath Mixer Taps, Shower Bath Taps, Stainless Steel Bath Taps ZHEJIANG KINGSIR VALVE CO., LTD. , https://www.kingsirvalves.com