Unit 307 Session 9 Testing cold water systems

​Testing cold water systems

Testing and commissioning procedures

Testing of installations is the first time we see whether the installation is watertight.
For pressure systems and sanitary systems, testing procedures are set out in the relevant British Standards and Regulations

​Pre-testing checks Before commissioning takes place:
● walk around the installation; check that you are happy that the installation is correct and meets installations standards
● check that all open ends are capped off and all valves isolated
● check that all capillary joints are soldered and that all compression joints are fully tightened
● check that sufficient pipe clips, supports and brackets are installed, and that all pipework is secure.

​Testing procedures

Testing procedures differ depending on the type of pipework installed.
The process involves filling the system with water to a specific pressure, letting it stand for a period of time to temperature stabilise and then checking it for pressure loss. Here, we will look at those different testing procedures.

Hot and cold water systems testing is detailed in BS 6700.

● Copper tubes and low carbon steel pipes: systems installed in copper tube and low carbon steel pipes should be tested to 1.5 times normal operating pressure.
They should be left for a period of 30 minutes to allow for temperature stabilisation and then left for a period of one hour with no visible pressure loss

https://colegycymoedd.sharepoint.com/:b:/r/sites/Level3Plumbing2224/Shared%20Documents/British%20Standards/6700.pdf?csf=1&web=1&e=x3Rn3r

​There are different tests for other pipework types, BS6700 gives 2 tests for plastic pipework.

Use the link below, look through the BS6700 document page's 57-59 and answer the questions on the next slides.

Open Ended

Describe test 'A' (Do not copy and paste)

Open Ended

Describe test 'B' (Do not copy and paste)'

Open Ended

What is the main difference you noticed between the tests for plastic pipework and that for ridgid (copper or L.C.S) pipework?

​Commissioning

Commissioning is the part of the installation where the system is filled and run for the first time. It is when we see if it works as designed.

The first task is to fill the system and check for leaks at the appliances. This is best carried out in stages so that sections of the installation, i.e. cold water, hot water, central heating, can be filled and tested separately.

At each stage of the filling process, the system should be checked for leaks before moving on to the next section.

Once the systems have been filled they should be drained down and flushed through with clean water, then refilled.

The water levels in WC cisterns, cold water storage cisterns, and feed and expansion cisterns (if fitted) should be checked for compliance with the relevant regulations.

​Check the flow rates at all taps to see if they deliver the flow rates demanded by the manufacturer’s literature, and check the operation of all controls, including thermostats and motorised valves.

To convert from litres per second (l/s) to litres per minute (l/m), simply multiply the l/s by 60.

For example:

0.3 l/s = 0.3 × 60 = 18 l/m

​To convert from litres per minute
(l/m) to litres per second (l/s),
simply divide the l/m by 60.

For example:

25 l/m = 25 ÷ 60 = 0.41 l/s

​​Water flow rate is measured in litres per second or litres per minute.

Multiple Choice

Convert 30 l/m into l/s

• 0.5 l/s

• 0.10 l/s

• 5.0 l/s

• 50 l/s

Multiple Choice

Convert .25 l/s into l/m

• 15 l/m

• 1.5 l/m

• 0.15 l/m

• 150 l/m

Multiple Choice

Convert 12 l/m to l/s

• 0.2 l/s

• 2.0 l/s

• 20 l/s

• 200 l/s

Multiple Choice

Convert 0.12 l/s to l/m

• 7.2 l/m

• .72 l/m

• 72 l/m

• 720 l/m

​PLANNED AND UNPLANNED MAINTENANCE

​Maintenance tasks on cold water services, appliances and valves are essential to ensure the continuing correct operation of the system.

The term used when isolating a water supply during maintenance operations is ‘temporary

decommissioning’.

Before undertaking the repair or replacement of components, we must first ascertain what the problem is.

The customer will be able to tell you what is happening with the component. They may not know the technical language but they will be able to explain the problem well enough for you to understand.

​Maintenance

There are basically two types of maintenance:

1. planned preventative maintenance

2. unplanned/emergency maintenance.

Open Ended

What do you think is meant by 'planned preventative maintenance'?

​Planned preventative maintenance (PPM)

Planned preventative maintenance is usually performed on larger systems and commercial/industrial installations.

It is performed to a pre-arranged maintenance schedule, which may mean out-of-hours working if the supply of water cannot be disrupted during normal working hours.

It is designed to stop problems from occurring by catching faults in their early stages.
Planned preventative maintenance could include:

• ​periodic system inspection – checking for leaks

• re-washering of float-operated valves

• re-washering and re-seating of terminal fittings and taps

• inspection and cleaning of cisterns

• readjustment of water levels in cisterns

• ​re-washering of drain valves

• cleaning of filters and strainers

• maintenance of water softeners

• checking the correct operation of stop valves

• checking flow rates at all outlets.

​A record of all repairs and maintenance tasks completed will need to be recorded on the maintenance schedule at the time of completion, including their location, the date when they were carried out and the types of test performed.


This will ensure that a record of past problems is kept for future reference.

Open Ended

Give some examples of what you think would be classed as unplanned/emergency maintenance

​Unplanned and emergency maintenance

​Unplanned and emergency maintenance occur when a fault suddenly develops, such as a burst pipe, or a small problem suddenly becomes a larger issue, such as a dripping tap or sudden loss of water.

Unplanned and emergency maintenance can include:

• burst pipes and leaks

• running overflows

• dripping taps

• loss of low-pressure, cistern-fed cold water supply due to faulty float-operated valves

• poor past installation practices, such as incorrectly positioned overflow pipes

• complete component breakdown necessitating the replacement of the component.

Multiple Choice

According to BS 6700, what is the recommended testing pressure for hot and cold water systems installed in copper tubes and low carbon steel pipes?

• Normal operating pressure

• Twice the normal operating pressure

• 1.5 times normal operating pressure

• Three times normal operating pressure

Multiple Choice

What is the primary purpose of commissioning in the installation process?

• Filling the system with water

• Identifying leaks at appliances

• Checking the operation of components and controls

• Checking pipework clipping

Multiple Choice

During commissioning, why is it advisable to fill and test different sections of the installation separately?

• To save water

• To identify leaks more efficiently

• To speed up the process

• To comply with regulations

Multiple Choice

What is the term used when isolating a water supply during maintenance operations?

• Permanent decommissioning

• Emergency decommissioning

• Temporary decommissioning

• Planned decommissioning

Multiple Choice

Which type of maintenance is usually performed on larger systems and commercial/industrial installations with a pre-arranged schedule?

• Emergency maintenance

• Unplanned maintenance

• Planned preventative maintenance (PPM)

• Reactive maintenance

Multiple Choice

What is one of the tasks involved in planned preventative maintenance?

• Emergency component replacement

• Periodic system inspection

• Temporary decommissioning

• Unplanned maintenance

Multiple Choice

When does unplanned and emergency maintenance typically occur?

• On a pre-arranged schedule

• During commissioning

• When faults are caught in early stages

• When a fault suddenly develops

Multiple Choice

What might be a scenario for unplanned and emergency maintenance?

• Periodic system inspection

• Burst pipes and leaks

• Checking flow rates at outlets

• Cleaning of filters and strainers

Multiple Choice

Why is planned preventative maintenance important?

• To identify possible faults in their early stages

• To perform emergency repairs

• To decommission the system temporarily

• To identify leaks during commissioning