FAQ´s

Frequently Asked Questions for Water Tanks:

What’s a potable water tank?
Water tanks can be classified as ‘potable’ and ‘non potable’. If you are storing clean water for human consumption, whether it be for drinking, prepping food or cleaning dishes etc, then a potable water tank is what you are after. All potable tanks must conform to the WRAS (Water Regulations Advisory Scheme) so that the liquid is safe for human consumption.

Non-potable tanks are for the safe storage of non-drinking water or for ‘not suitable’ for human consumption, in many different environments and applications. Non-potable tanks can be used in applications like rainwater harvesting, irrigation, agriculture & horticulture and commercial purposes where mains water is not available.

The difference in classification between the two comes from the materials used during the manufacturing process, specifically the type of plastic used to line the inside of the tank which comes into contact with the contained water. Non potable tanks are more porous, making it easier for the bacteria to grow and can sometimes let off gases which can contaminate the water. The WRAS approved material lines the inside of the tank, making the tank fit for human consumption, either ingested or used on the skin.

What materials are the plastic tanks manufactured from?
Plastic water tanks can be made of lots of different materials, however the majority of tanks we offer are made from either a medium density polyethylene (MDPE) or a high density polyethylene.

What’s a standard hose pipe size?
UK hose pipe diameters range from ½” to ¾” inch diameters. The majority of standard size garden hoses are 3/4” BSP, however we do offer accessories for the ½” hose, if required.

What outlet do I require?
The majority of our water tanks come with an outlet as standard. We can offer a range of water tanks where the tanks can either ‘Drilled’ or ‘Undrilled’. ‘Drilled’ meaning allowing water to escape from the tank via the outlet, whereas ‘Undrilled’ is when the outlet will remain sealed, preventing liquid from coming out and ensuring the contents of the tank is only touching plastic.
Plain tanks (with no outlets) can also be offered.

What is a Byelaw 30 (or 60) Kit?
Byelaw 30 kits and Byelaw 60 kits consist of a set of components designed to protect the water in a cistern from contamination. They are intended for potable water cisterns, such as the cold water storage cistern in the loft. The variation in name is due to the separate legal systems in the UK, namely England and Wales, and Scotland. The main difference between the two kits is the diameter of the overflow. The Scottish Byelaw 60 stipulates a larger diameter overflow (38mm/1.5", compared to 22mm/3/4" for England & Wales).

The kits generally consist of a screened overflow pipe, an overflow dip tube, a rubber grommet for the expansion/vent pipe, and a breather fitting. Along with the tank lid, they are vital in keeping the water free from dirt and debris. 

The cold water storage tank is a key part of your plumbing system. Without any protection, foreign objects such as dust, loft insulation and insects can get inside. In some cases, even rodents and birds may fall in, if they can get into your loft. Byelaw 30 and byelaw 60 kits are vital for protecting your system from blockages and contamination. 

Baffled Water tanks, what are they and when are they recommended?
Baffled water tanks are tanks with an integral wall system, which is primarily designed to strengthen and support the structure of the tank, when the tank is full of water.

Due to the structure of the baffles they can also be used for transporting water. The Baffles disrupt the movement of water, from surging from one side to the other. However, if you are transporting water, water tanks can be extremely hazardous when transporting large volumes of water. Please make sure the water tanks are installed and secured correctly, by a suitable qualified person before transportation. Baffled water tanks are an ideal solutions for car valeters, window cleaners or anyone who has to transport liquids using plastic water storage tanks and containers.

What is a GRP tank?
Glass Reinforced Plastic tanks are made from high quality GRP material manufactured to BS EN 13280:2001, are suitable for all cold water applications, insulated tanks are also suitable for external applications, and are fully WRAS approved.

Benefits of GRP over steel or plastic
Most GRP tanks are supplied fully pre-insulated with PU foam fully encapsulated within the GRP laminate, GRP tanks come in a wide range of standard sizes and can also be supplied bespoke to suit your specific size and configuration requirements.

Whats the difference between an AB or AG air gap tank?
An AG type airgap provides mains water protection from fluid category 1-4 with standard lid arrangement for an inlet float valve fitted in the body of the tank, and an AB type air gap, also known as category 5, is when a raised float valve housing is fitted with a spill over weir in addition to the overflow in the body of the tank.

When is a 1 piece, 2 piece or sectional tank used?
1 & 2 piece tanks are available from 45 to 12,000 litres, sectional tanks can be supplied from 125 to 2,000,000 litres. Usually where access permits a 1 piece can be used without any assembly needed, if access is restricted a 2 piece tank can be installed and the top and bottom halved bolted together on site. Sectional tanks are for where access restrictions or other conditions deny the installation of one and two piece tanks. They comprise of individual bolt-up panels which are assembled on site.

Sizing a float valve for my GRP tank, which one would I need?
A float valve will usually be sized to suit your incoming mains water supply, so if you have a 25 mm incoming mains you will need a 1” float valve. If we supply the float valve with your tank we will size and supply the overflow to suit this.

What is a WRAS tank and is it compulsory?
The Water Regulation Advisory Scheme sets legal requirements for the design, installation, operation and maintenance of plumbing systems, water fittings and water-using appliances. These Regulations and Bye laws apply in all types of premises supplied, or to be supplied with water by a water company. All of our insulated GRP tanks are fully WRAS approved, so can be connected to a mains cold water supply. These regulations do not apply where a property uses a private water supply and does not have a supply of water from a water company.

There are lots of optional extras on the GRP tanks, what are they and are they required?
Our GRP tanks are usually supplied without any connections, as many customers supply and fit their own. However we can supply a comprehensive range of items including inlet float valves, outlet connections and other fittings to suit your individual application. Please contact us at hello@thetankshop.co.uk to discuss or request a quote for your requirements.

Do you supply pumps with the GRP tanks?
If you require a booster pump, you must fit a break tank to the incoming mains water supply to connect to the pump set. Our GRP tanks are ideal for break tanks. We can supply a wide range of booster sets where a break tank is needed.