6189_l2u10_ppt6
Transcript of 6189_l2u10_ppt6
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Level 2 NVQ Diploma inPlumbing and Domestic
HeatingUnit 010 No 6
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Materials and connections
Objectives
By the end of this session you will be able to:
Describe a range of sanitary materials.
Explain how they are connected.Identify below ground drainage system.
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Types of materials
The main materials used on above ground discharge are made
from plastic and are called PVC u, MuPVC and ABS which can
be either solvent welded or used as push fit fittings.
Polypropylene is push fit only. Some contract will demand that
solvent weld fittings are used.
The way we install installations is subject to a code of practice
BS 8000-13. with the title, Workmanship on building sites.
Code of Practice for above ground drainage and sanitary
appliances. 1989
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Push fit fittings
Type of waste pipe Advantages Disadvantages
Push fit water tight jointing
easy
Pipe is light
Easy to decommission
Allowance for thermal
movement
Immediate testing
after fitting
Pip can sag
Joints can
disengage
External
installation
degraded by UV
light
Advantages and disadvantages of push fit installations
Table 1
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Solvent weld fittings
Type of waste pipe Advantages Disadvantages
Solvent weld Rigid and resist sagging
Neater and more slim
line in appearance
Permanent reliable
jointing
Resistant to most acids.
Alkali or chemicals
Permanent joints
restrict
repositioning
Immediate testing
not permissible
Ventilated area
required because
of fumes while
jointing
UV light will
deterioratepipework
Advantages and disadvantages of solvent weld
Table 2
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Types of materials
Cast iron has been
used for many years
because it is a robust
and reliable material
but it is difficult to
work with. Thispicture shows
pipework connected
with timesaver
connections which
comprise of a rubber
sleeve and two iron
clamps which arebolted together to
make a water tight
seal.
Picture no 1
Access point
located above
flood level ofhighest appliances
Timesaver
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Types of materials
In the past jointing was made by either hot lead or lead wool and caulking.Sometimes this is specified on ancient monuments refurbishments or special job
requirements. You may still have to work on cast iron in refurbishment work but
nowadays it is mainly required for public building and hospitals.
Picture no 2
Horizontal
Cast iron
socket
caulked with
lead
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Waste connections to a soil stack
Boss pipe: this is a manufactured fitting with formed raised
circular profiles which have to be drilled out and an adapter it
then fitted into the newly made hole to receive a waste pipe.
Strap boss: once a hole has been drilled in a soil pipe this
fitting is then glued and strapped on over the hole and thewaste pipe is connected as above.
Waste pipe manifold: this is a manufactured fitting which
often sits on the floor in the corner of a bathroom ant the
purpose made holes accept 32mm and 40mm waste pipes via
the special designed grommet seals. This device also preventscross flow.
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Waste connections to a soil stack
Strap boss ready for installation (A) and one in situ (B)
A
B
Picture no 3
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Waste connections to a soil stack
Boss pipes in situ
B
Picture no 4
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Waste connections to a soil stack
Waste pipe manifold fitted at floor level
B
Picture no 5
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Access to pipework
The Building Regulations: require that there is access to above
ground drainage systems for maintenance, cleaning and
blockages.
This can be achieved by the installation of:
Purpose made access fittings
Access plugs in soil junctions
Access plugs in waste pipe
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Access to pipework
PVCu access at street level next to Cast Iron rainwater shoe. Cast Iron access at high level.
Picture no 6
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Access to pipework
Access points on PVCu and Cast Iron waste pipework
Picture no 7
Access points
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Soil stack connections to a drain
Drain connections are made from a range of materials. Older
properties tend to have either salt glazed earthenware or cast
iron which requires a strong 2:1 ratio to make a robust seal.
PVCu connections and hep sleeve for clay piping are bothmade with Push fit connections and silicone lubricant allows
ease of installation.
A multi-fit adapter can connect almost any combination of soil
pipe materials.
It is important to understand what type of below ground
drainage system exists before making a connection.
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Types of soil stack drain connections
Drain connectionsSalt glazed earthenwareCast iron
PVCu
Hep sleeve
Multi-fit adapter
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Types of soil stack drain connections
Salt glazed earthenware (exposed sections)
Picture no 8
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Types of soil stack drain connections
Multi fit adapter to
connection PVCu above
ground pipework to a spigot
leading to cast iron below
ground pipework. When
fitting a PVCu pipe to a cast
iron socket a different
adapter is required.
Picture no 9
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Quick questions
Which British Standard gives guidance on workmanship when
installing fittings on AGDS?
Name the three main plastic used in waste fittings and
pipework.List the advantages and disadvantages of push fit and solvent
weld fittings.
What are the options available for connection waste pipes to
soils stacks?
How can a connection be made with a cast iron below grounddrainage collar?
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Below ground drainage
The purpose of a below ground drainage system is to take soil
water aka black water and rainwater to a sewer which is
located in the road and then carry this effluent to a sewage
plant where it is processed.
There are three types of below ground drainage systems:
The Separate system
The Combined system
The Partially Separate
(Also Known as Partially Combined system)
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Separate system
With this system foul water and rainwater discharge
individually into separate drainage systems and then into
separate sewers in the street. The foul water is conveyed
directly to the sewage plant where it is processed and the
rainwater flows to the nearest water course.
This system is one most favoured by the local authorities.
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Separate system
Advantages Disadvantages
The sewage plant does not
become overwhelmed when
it rains heavily
Trapped gullies are not
required for the rainwater
pipework
Two drain means that it is
expensive to install
The foul drain does not benefit
from rainwater flushing
Risk of making wrong
connections to the rainwater
Greater number of inspection
chambers required
Advantages and disadvantages of a separate system
Table 3
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Separate system
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Combined system
With this system both foul water and rainwater discharge into
a common sewer making connections to the drains more
simple. This also makes it economic to install.
The Building Regulations no longer recognises that this is a
viable system on any new installations.
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Combined system
Advantages Disadvantages
Drain maintenance is easier
Cheaper to install
Make wrong connections
impossible
Flushing of drain achieved
when it rains
Expensive with regard to
sewage processing as excessive
rainfall in unwieldy to handle
with both types of discharge
passing through the process at
the same time
Advantages and disadvantages of a combined system
Table 4
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Combined system
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Partially separate system
This is a combination of the combined and then separate
system. Two drainage systems are used. One system carries
the foul water and part of the rainwater while the other carries
the rainwater only. Water which is not collected by the surface
water drain is collected in a soakaway.
A soakaway is a pit usually measuring 1m3 which is cut out of
the round 5 m away from the building. The hole is filled with
gravel to allow rainwater to evenly soak away into the water
table.This system is also known as the partially combined system.
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Partially separate system
Advantages Disadvantages
Isolated rainwater
connections to a foul drain
can reduce costs
Rodding eyes can used
instead of expensive
inspection chambers
When installing foul water
outlets care must be taken to
ensure the correct connection
is made
Advantages and disadvantages of a deparate system
Table 3
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Partially separate system
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Soakaway
Soakaway
Illustration no 4
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Connecting appliances to existing
below ground drainage systems
Any connection will depend on the material the below ground
drainage system is made from. Kitchen sinks and basins may
discharge into a back inlet gully providing the waste pipe
protrudes through the grille but above the water level in thegully to ensure that there is an air break and no ingress of foul
air can occur.
A WC can connect directly into a ground floor drain by using a
WC pan connecter. There are many adapters to choose from
ranging from 75-110mm which can allow the fitting of olderand more modern WC pans.
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Connecting appliances to existing
below ground drainage systems
WC can connect
directly into a
ground floor drain
by using a WC pan
connecter. There
are many adaptersto choose from
ranging from 75-
110mm which can
allow the fitting of
older and more
modern WC pans
An angled WC pan connector
WC pan spigot enters here
This spigot fits into the
socket connection on a stack
Picture no 12
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Quick questions
What are the 3 main below ground drainage systems?
Which one is preferred by the local authorities and why?
Which system is cheaper to install but more expensive to
process?What are the dimensions involved in installing a soakaway?
How would you install the waste of a sink into a bag inlet gully?
Stretchers If a foul smell was coming from a soakaway after a
new washing machine had been installed what do you thinkcould have happened?