Things called Codes of Practice (CoPs) are designed to make recommendations related to maintaining good working practices. The codes are not legally binding as documents but are used by people like clients and Architects. A Croydon Plumber has codes of practice.The Water Supply (Water Fittings) Regulations 1999.These particular set of Regulations are applicable only in England and Wales, and are the replacement for the old Water Bye-laws. These Regulations are national and are made by the Governments Department of the Environment, Food and Rural Affairs (DEFRA), whereas the Bye-laws that they replaced were made locally and applicable in that area, say, Yorkshire Water, Thames Water, Northwest Water etc. They are mentioned as they cover materials and substances in contact with water. Croydon Plumbers obey the regulations.European Standards.The standards for europe begin with the letters EN and are then followed by the standard number, in just the same way as for British Standards. When a product is certified to an EN standard it indicates that the manufacturer has taken the product through a multitude of tests that are regularly checked under EC Quality Control Schemes.International StandardsThe International Standards begin with ISO and are followed by the number, for example ISO9000, which is a standard for quality.Water Regulations Advisory Scheme (WRAS).This was previously known as the Water Bye-laws Scheme. The WRAS has been carrying out the testing on fittings for many years and will keep advising on Water Regulations in the future. Part of their work is to produce a Fittings and Material Directory, in which is listed all approved fittings and is a very important guide for all who aim to comply with or enforce The Water Regulations. Materials and Their Properties.The term properties of materials refers to just how strong they are, how good they are at the conduction of heat or electricity and how flexible they are. Material properties can be measured by the way materials react to a variety of influences.