Plumbing:-
1) Pump
head:
Total Head = Total Suction head – total discharge head
Total suction head = total ht from the centre
line of pump to max ht of pipe run + Total friction head + total surface
pressure head (is 0 wn tank is open)
Total discharge head = total ht from the
centre line of pump to max ht after discharge + Total friction head + total
surface pressure head.
2)
Pressure head is a term used in fluid mechanics to represent the internal energy of a fluid due to the pressure exerted
on its container. It may also be called static
pressure head or simply static head (but not static head pressure). It is
mathematically expressed as:
where
is
pressure head (Length, typically in units of m);
is the specific weight (force per unit volume, typically N/m3 units)
is acceleration due to gravity (rate of change of velocity, given in
m/s2)
Note that
in this equation, the pressure term is gauge pressure, not absolute pressure.
 |
Where Fr = Friction loss = 0.1
L= length
Pr = Pressure head
3)
Total Static pressure:
TSP =
Static pressure + (Density x (Vel)²)
2
*Duct Static Pressure = Total Friction loss
(L/D*0.0195*VP) + Dynamic loss (Dinamic
loss cofficient*VP) {note l & d are in feet & VP = (velocity/4005)^2}
4) 1
psi = 6894.7 Pa = 0.0689 bar ; 1 bar = 100,000 Pa =29 inhg = 401 inh2o .
5) How
to find pipe dia = GPM * Velocity (FPM) {you will get friction and pipe size
from the graph}
6) Isolating
valve = Ball valve = gate valve = Butterfly valve.
7) Check
valve = non return valve
8) Pressure
reducing valve - Whenever pressure increases the limit, it will regulate
pressure and it is connected to BMS system.
9) Double
check valve = Back flow preventer
10) What
are the fittings of faucet drainage etc., - Mixer, valves, flexible connecting
pipes, etc..
11) How
to determine stack sizes and how many types are there. – Vent stack, Waste
stack, Soil stack. Varies with load on each floor.
12) What
are the normal codes followed for drainage and plumbing in ksa.
1) NPC
= National plumbing Code.
13) What
are the software used for calculating the pipe sizes and hot water cal etc.,:-
epipesizer, elite pipe, pocketpipe, s-pipe, PP calculator, Etc.
14) What
is use of U-Trap and where it is used? It is used in Drain connection as water
seals/smell.
15) What
should be the max distance between sewer line & portable water line? 3
meter.
16) How
much size of clean out is provided for sewer pipe below 10" dia? 6"
17)
What are the different pipe material used in
plumbing installation?
CI,Acid resistant
CI,Bituminous fiber pipe,virtified clay pipe,Lead pipe,Galvanized steel pipe, Galvanized
wrought iron pipe,brass pipe,copper pipe,Plastic & synthetic pipe, UPVC,
CPVC.
18)
What are the impotant factor to consider while
installing waste pipe?
Selection of right
kind of material,
Conservative use of
fittings.
Right location of
cleanouts.
Right pitch or slop
of pipe line.
Manner of joining
the pipe.
19)
What should be the distance between manholes? 15
m.
20)
What are the different materials used for
underground water supply? uPVC (Cold water), cPVC (Hot water), ..
21)
How to find friction in pipes? There is a graph
on which if you know two values you can find the others … the graph copy is
attached.
22)
Stiffness of GRP Pipes: 2500 N/m2 (this class of
pipe can be used for the earth load(truck load+ earth load) depth that is 2 m
to 4m which will not exceed the long term deflection of 5%), 5000, ( this class
of pipe can be used for the pipes in trench depth (or depth of cover) of 7m),
and
10000 N/m2 ( this class is used for the pipes with depth
of cover of more than 7m like for 10 m).
23)
1N/m2 = 1Pa.
24)
Pipe Spool: - The term "pipe spool" or
"spool piece" refers to a prefabricated section of a piping system
that includes the pipe, fittings and flanges that are pre-assembled in the
fabrication facility and then transported to the field. The reason for
pre-assembly is that hoists, gauges, material and tools are available for the
assembly in a controlled environment. The size of the spool pieces is limited by
factors related to transportation to the site and ability to handle the spool
piece at the site during assembly.
25) Efficiency
of Pump = GPMxTotal Headx100/Input HPx3960.
26) Tank
to Pump – Service connection details (shown in the ‘Plumbing Notes file’).
27) Class
of water supply pipes upvc pvc cpvc pipes? – (Shown in ‘Plumbing Notes file’)
