Module 1 Mild Steel Pipework Flashcards
What % of carbon is in mild steel?
mild steel is an alloy and up to 0.2% carbon hence the term LOW CARBON STEEL
What is mild steel pipe also known as??
Low Carson steel pipe
What finishes does mild steel come in?
Painted red and also galvanised
What is mild steel used for?
Hot water heating systems (no air in them) and gas supplies only
What would happen if used with fresh water?
It would be liable to corrosion problems
How is galvanising steel done?
By hot dipping it in molten ZINC
What should not be done to galvanised tube?
Never be welded as heat would remove the zinc coating and be open to corrosion
Mild steel pipe explain about it??
Comes in 6m lengths , plain or threaded ends , sizes from 8mm to 200mm and above , comes in 3 thicknesses
What is medium grade mild steel used for?
Low pressure heating systems and gas installations
What is heavy grade steel used for??
High temp hot water and heating systems also steam installation and acetylene gas
What is schedule 40 & 80
Used in process industries 1-blue band. 32mm 2-red band 40mm 3-schedule 80 50mm
What are the 3 ways of joining mild steel pipes??
Threaded joints using stocks and dies , welding joints using acetylene , victaulic joints using electric grooving machine
What is a threaded joint?
BSPT this is a tapered thread that thightens when screwed together
What are the two types of threaded joints?
A male external and a female internal
What are the safety hazards on the electric threading machine?
Long hair, loose protective clothing, jewellery, rings, oils, spillages , wearing gloves, long pipe work rotating, resting on a moving machine,
What are lubricants used for and when?
Used to cool and lubricate cutting die and work piece
What are unions used for??
To allow final joints to be made or to facilitate removal,
Name the 3 joints used when making a union ?
Hexagon Union / flanges / longscrew threads
Where are flanges used?
In industrial installations where very large valves or controls may have to be replaced, they are fitted to the pipe BSP threads
What is used between flanges?
The material used between flanges depends on what fluid the pipe is carrying INSERTION RUBBER is suitable for many appliances
What type of gaskets can be used?
CAF gaskets and halite , spiral wound gasket , insertion rubber
What is the name of the material is used for a plumber to make a gasket on site?
CAF GASKETS and halite
Where is spiral wound gaskets used most commonly?
Gas
How is victaulic joints made?
By cutting a single groove in the pipe which a steel clamp fits and a rubber washers are used to seal
Where is victaulic joints used?
To fabricate fire fighting systems or large bore cold distribution systems
Why is it essential to remove the burr? What will happen if not removed?
Reduction in heat carrying capacity / reduction in water flow delivery / noise creation / air formation n fresh water systems /
What is used to remove burr?
A pipe reamer , a de-burring tool or a file
What are the two ways to bend mild steel??
MACHINE BENDING/ HEAT BENDING
What should be ensured when using a HYDRAULIC benders??3 things
The correct size inside former is attached / the 2 rear formers are in the correct place / ensure that the formers are turned to suit the pipe
Where should the bending line be positioned for 90’ ?
The centre of the former
What should be done to get the correct measurement for 90’ ?
Subtract the full inside diameter of the pipe
To mark out a pipe to a given radius use this calculation
- ♊️x D ➗4 for 90’ bend - ♊️xD➗8for 45’ bend - ♊️xD➗6 for 60’ bend - ♊️xD➗12 for 30’ bend
When preparing the pipe for sand bending it’s important to?
Use only clean dry sand / pack the pipe tightly a packing bar / ensure plug is a tight fit into reamed pipe / only bend when the pipe has reached an even dull red all the way round
What will happen if u rush sand bending?
Buckling (incorrect heat) thinning (incorrect heat) ovality (sand not tight enough) uneven radius (under or over bending) incorrect radius (marked out wrong) heat marks (overheating)
What must be done to pipe work going through a wall?
Sleeved or timber joists
What can happen if pipe work is not supported properly??
Damage or failure under service conditions or faults such as air locks
What should be considered when supporting pipe work?
Type of surface Which fixings are going into / the weight of the components to be fixed / what way it is been fixed for pipe runs and levels
What’s the best material should clips be made from?
If possible the same material as the pipe or fitting
