Introduction To Plumbing

You have made the decision to learn about plumbing and you are probably looking forward to working in the industry. In this section, we explore what a plumber actually does and give you
an insight of what to expect on site.

What do we mean by ‘plumbing’?
Anyone new to the industry will probably have a view of what a plumber does. How would you describe plumbing? Think about this for a while and jot down a few notes. We tend to find when speaking with people that their view of plumbing is of someone clearing a blocked drain, or repairing burst pipes. Whilst a plumber does this work, the job is much more involved than that.
Generally, we think that plumbing meets people’s basic requirements by:

• Keeping them healthy and clean by providing cold water for drinking, hot water for washing and sanitation systems for the removal of waste products
• Keeping them warm with the help of hot water heating systems
• Meeting the above requirements together to ensure maximum comfort and convenience for them by providing heating, hot and cold water systems and sanitation 365 days a year, and 24 h a day.

Explore the plumber’s role a little further and you will see that
most plumbers usually carry out the: Installation, Service, Maintenanceof a wide range of domestic systems such as:

• Cold water, including underground services to a dwelling
• Hot water
• Heating systems fuelled by gas, oil or solid fuel
• Sanitation (or above ground drainage) including the installation of baths, hand wash basins, water closets (WCs) and sinks
• Rainwater systems, gutters and fall pipes
• Associated electrical systems

In fact, you will see that the above list matches the content of the Technical Certificate. In addition to the systems, the plumber will also have to work on the appliances and components contained within them. Here are a few examples:

Storage vessels, cylinders, cisterns

Sanitary appliances, sinks, baths, WCs, washbasins

Domestic appliances including washing machines and dishwashers

Heat exchangers, boilers, radiators

Pumps, accelerators and motorised/isolating valves

Gas appliances (natural or Liquefied Petroleum Gas (LPG), boilers, water heaters, cookers and fires)

Pipe materials, fittings, fixings, controls that constitute the
above systems.

Plumbers also work on:

• Cabling and electrical components
• Sheet weatherings, aprons, back gutters, step flashings, soakers, lead slates.
  

The Level 2 Technical Certificate focuses on all aspects of domestic plumbing work. Some plumbing companies however, specialise in specific work such as central heating, or industrial/ commercial, which is basically working on much bigger systems in non-domestic premises.

So, we are now beginning to build up a picture on the extent of a plumber’s job. What skills and knowledge do you think a plumber needs in order to be able to carry out the job competently? Here are our thoughts on what a competent plumber should be able to do:

• Follow Health and Safety legislation and guidance at all times
• Thoroughly plan the job including making sure that all the tools, materials and equipment are present on the job
• Agree a schedule of work with the customer or client
• Provide a cost estimate for the job
• Prepare the work location, making sure that there is adequate access
• Protect the customer’s property
• Mark out, measure and work out the installation requirements
• Fabricate, position and fix system components
• Pre-commission (including testing), commission and de-commission systems
• Service and maintain system components
• Work effectively with customers, workmates and other site visitors
• Work in an environmentally friendly manner
• Promote the products and services of the plumbing business.
  
  We also think that the plumber should have a working knowledge of:
• Regulations
• Codes of Practice
• Principles of plumbing systems including basic design
• Where to find manufacturers’ technical data
• Health and Safety legislation and guidance
• Commercially agreed standards.

A plumber must also be able to read and interpret details contained within a number of information sources including drawings, specifications and manufacturers’ catalogues.

water distribution network systems configuration

In general, water distribution systems can be divided into four main components: (1) water sources and intake works, (2) treatment works and storage, (3) transmission mains, and (4) distribution network. The common sources for the untreated or raw water are surface water sources such as rivers, lakes, springs, and man-made reservoirs and groundwater sources such as bores and wells. The intake structures and pumping stations are constructed to extract water from these sources. The raw water is transported to the treatment plants for processing through transmission mains and is stored in clear water reservoirs after treatment. The degree of treatment depends upon the raw water quality and finished water quality requirements. Sometimes, groundwater quality is so good that only disinfection is required before supplying to consumers. The clear water reservoir provides a buffer for water demand variation as treatment plants are generally designed for average daily demand.

Water is carried over long distances through transmission mains. If the flow of water in a transmission main is maintained by creating a pressure head by pumping, it is called a pumping main. On the other hand, if the flow in a transmission main is maintained by gravitational potential available on account of elevation difference, it is called a gravity main. There are no intermediate withdrawals in a water transmission main. Similar to transmission mains, the flow in water distribution networks is maintained either by pumping or by gravitational potential. Generally, in a flat terrain, the water pressure in a large water distribution network is maintained by pumping; however, in steep terrain, gravitational potential maintains a pressure head in the water distribution system. A distribution network delivers water to consumers through service connections. Such a distribution network may have different configurations depending upon the layout of the area. Generally, water distribution networks have a looped and branched configuration of pipelines, but sometimes either looped or branched configurations are also provided depending upon the general layout plan of the city roads and streets.

Urban water networks have mostly looped configurations, whereas rural water networks have branched configurations. On account of the high-reliability requirement of water services, looped configurations are preferred over branched configurations. The cost of a water distribution network depends upon proper selection of the geometry of the network. The selection of street layout adopted in the planning of a city is important to provide a minimum-cost water supply system. The two most common watersupply configurations of looped water supply systems are the gridiron pattern and the ring and radial pattern; however, it is not possible to find an optimal geometric pattern that minimizes the cost.

(taken from : DESIGN OF WATER SUPPLY PIPE NETWORKS, Prabhata K. Swamee - Ashok K. Sharma. )

Hybrid system “Preaction-system"

OK, here we go from the previous post,

A combination of previous types , 2 subcategories of Hybrid system do exist

• Single interlock that act like dry system except these systems require that a “preceding” fire detection event, typically the activation of a heat or smoke detector, takes place prior to the “action” of water introduction into the system’s piping by opening the pre-action valve.
• Double interlock similar to deluge systems except that automatic sprinklers are used. Activation of either the fire detectors alone, or sprinklers alone, without the concurrent operation of the other, will not allow water to enter the piping

Type of Sprinklers

Type of sprinklers

-Wet pipe systems

They are simple, with the only operating components being the automatic sprinklers. An automatic water supply provides water under pressure to the system piping. All of the piping is filled with water. Until sufficient heat is applied, causing one or more sprinklers to fuse (open), the automatic sprinklers prevent the water from being

discharged.

Operation - When an automatic sprinkler is exposed to sufficient heat, the heat sensitive element (glass bulb or fusible link) releases, allowing water to flow from that sprinkler. Sprinklers are manufactured to react to a specific range of temperatures.

-Dry pipe systems

Water is not present in the piping until the system operates. When one or more of the automatic sprinklers is exposed to sufficient heat, it opens, allowing the maintenance air to vent from that sprinkler. Each sprinkler operates individually. As the air pressure in the piping drops, the pressure differential across the dry pipe valve changes, allowing water to enter the piping system. Water flow from sprinklers needed to control the fire is delayed until the air is vented from the sprinklers. For this reason, dry pipe systems are usually not as effective as wet pipe systems in fire control during the initial stages of the fire.

-Deluge systems

"Deluge" systems are systems that have open sprinklers, the heat sensing operating element is removed or specifically designed open sprinklers, so that all sprinklers connected to the water piping system are open. These systems are used for special hazards where rapid fire spread is a concern, as they provide a simultaneous application of water over the entire hazard. They are commonly seen as preventive measures to prevent egress of fire from an external source. Water is not present in the piping until the system operates. Because the sprinkler orifices are open, the piping is at atmospheric pressure. To prevent the water supply pressure from forcing water into the piping, a deluge valve is used in the water supply connection, which is a mechanically latched valve. It is a non-resetting valve, and stays open once tripped.