Smart Choice

For Pipes & Fittings

Dec 17, 2017 |

Your house’s plumbing is basically like your body’s nervous system. Everything is connected in one way or the other, and leaks can be extremely harmful. Piping and fitting is thus a serious business with usage of materials that can survive high pressure and high temperature as well. If you were looking to take some tasks of plumbing yourself, buy the right material, or wanted a second opinion than your plumber, we got your back! At think before buy, we take care of all the mumble jumble research to help you make a smart choice.

Materials and Type
Your house will have multiple pipe lines for multiple purposes. Every household piping starts from the common government line to bring water to your compound and then to the water tank and respective taps. There’s another line from waste collection to the sewage line. The multiple purposes also require multiple kinds of pipes.

Galvanized Iron(GI) pipes used to be a popular choice. But since they’re expensive as a material and equally expensive to make, they are being replaced. HDPE High-density polyethylene (HDPE), Chlorinated polyvinyl chloride (CPVC), unplasticized polyvinyl chloride (uPVC), and polypropylene random copolymer (PPR) pipes come much cheaper, do not get rusted, and have a longer life.

GI pipes still cover 10% of the market today. Since pipes in streets need to survive high pressure like from automobiles running on them and other surroundings, they are still found in some of the public water supply units and government projects.

However, since HDPE pipes have a high strength to density ratio, all recent government projects including the Melamchi Khanepani Project have been using HDPE pipes instead. They can resist the high pressure as city street pipes. Most rural areas also use HDPE or GI pipes. All HDPE pipes used in these projects are made in Nepal have a Nepal Standard approval.

For your house, when you connect the street pipe to your compound, you are required to use strong GI or HDPE pipes. However, your HDPE pipes need not be NS certified and can be made of recycled materials. While NS certified HDPE pipes sell for NRs. 225 per kg on average, the recycled ones start from as low as NRs. 90/- per kg.

Once the pipe reaches your compound, you separate your water lines into two parts- The incoming pipe (for clean water to the tank and then to respective taps) and the outgoing pipes (for waste water from sinks, rainwater collection, and other pipes connecting to the sewage).

UPVC pipes, also known as PVC pipes in the market, are used for outgoing pipes that collect water from the house to the compound or the sewage pipes. It’s strong and resistant to chemical erosion. However, they cannot be used to transmit drinking water.

CPVC or PPR pipes are used for incoming pipes to transmit water from water supply sources to the tank and to respective taps. CPVC pipes are fairly new in Nepal while the PPR pipes have been manufactured in Nepal since almost 15 years. CPVC pipes are held together with glues and a little more expensive from the PPR pipes that are held together through heat fusion.

Fittings are parts used to connect pipes. They come in different angles and types to serve different purpose connections. These connectors are assigned a gender as Male(M) or Female(F). The F is generally a receptacle that receives or holds an M. Few most common kinds of fittings are:
(a) Elbow: They’re shaped like human elbows that usually come in 90° or 45° joints and are further categorized by length and diameter of the pipe. A 45° elbow, also known as short radius or regular elbow has same diameter as the pipe while a 90°, also known as long radius or sweep elbow is 1.5 times the pipe diameter.
(b) Coupling: They are straight connector that come in two types. Regular coupling come with a ridge in between to ensure both sides are inserted in equal amounts. Slip Coupling comes without this ridge.
(c) Union: The union is the same as Coupling, except it comes in three parts( union nut, tail piece, and thread piece) that can be unfastened for future repairs.
(d) Tee: Shaped like the letter T, it is the most common pipe fitting used to combine or divide the flow. The two ends are called the run and the branch line connection in the middle is called the bull.
(e) Reducer: These fittings are used to fit two pipes of different diameters.

While GI pipes need metal fittings, other plastic pipes can use either plastic or metal fittings depends on where it is required. Mostly, sinks and bathrooms use metal while the rest of the joints use metal.

While the pipes are processed and manufactured in Nepal, their raw materials are not made in house. Panchakanya Group, one of the largest manufacturers, brings its raw materials from Sesikui Chemicals in Japan with National Sanitary Foundation Certification for their CPVC pipes. Nepatop produces PPR pipes, HDPE pipes, CPVC pipes and UPVC pipes with raw materials from South Korea, China, Malaysia, and Soudi Arabia.

Considering how installing pipes and fitting is a long term investment that might require regular servicing, it is always recommended that the user not only know the raw material and standard the product has passed, but also the kind of brand it represents. Choosing a brand can come from asking your engineers, relatives, to your local customer feedback.

The Department of Food Technology and Quality Control has laid out standards for the production of these pipes with requirement as specific as the width of the pipes. The ones that pass these standards get an NS stamp which is a mandatory requirement for governmental water supply projects. Other certifications you can look for is the Indian Standard(IS) certificate approved by the Government of India.

HDPE pipes require an NS-40 certification while the uPVC require an NS 206. Neither CPVC nor PPR pipes have gotten any direction for Nepal certification yet. Most of us build houses once in a lifetime. The pipes that go inside the walls and tiles might not make the first impression but as the nervous system of your home, they require careful selection with reliable quality and brand. Think before buying and make a smarter choice!

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