Answer / surya v kuchibhotla

The classification is made based on the longitudinal and
spiral reinforcement and based on the three edge bearing
test loads. Also it depends on the reinforcement provided in
socket of pipes for rubber ring joint.
NP-1 Class pipes are unreinforced concrete, non pressure
pipes. These are used for drainage and irrigation use above
Ground level or in shallow trenches.
NP-2 class are reinforced concrete pipes, light duty and non
pressure pipes.
NP-3 class are Medium duty non-pressure pipes used for
drainage and irrigation use, for culverts carrying medium
traffic.
NP-4 class are Heavy duty, reinforced concrete pipes.Used
for drainage, Irrigation, culverts with heavy traffic and
are suitable even for Railway loading.

Answer / sjtbehera

yes i agree with Mr. surya v Kuchibhota.

thia is as per IS:458-1988

Answer / deep kotadiya

Basically on field terms the difference to understand its usage is
NP stands for non pressure
And NP 2, NP 3, NP 4 are categories of pipe to be layed according to the demand, factors including depth, load and volume or flow in the pipe.
NP 2 for shallow depth and least flow
NP 3 has more steel than NP 2 and can be layed in more depth
NP 4 more steel than NP 3 in order to resist in deeper depth and max. Load
All pipes works economically under the gravitational force, still pump house are there in order to tackle difficulties.

Is there is any formula for calculate the correct length of rebar while it bending in 45 degree/90 degree and cranking???

2 Answers   L&T, NBCC,

---

which"s we should use for concrete ppc or opc?

9 Answers   Wipro,

---

What are the Tests required to check the Quality of bar?

3 Answers  

---

I Have concrete mix with 440kg opc and having 37 mpa strengh in 7days while in 28 days only 42mpa can anybody tell me the reason for the same.

4 Answers  

---

what are the criterias for designing a school lab? for e.g a chem lab.Does it depend on room size or no. of students?

3 Answers  

---

---

32mm bar column lapping we use welding binding what is dimension of welding as per stander code? 

2 Answers   RMC,

---

Differentiate first angle & third angle projection?

0 Answers  

---

what is the relation between pitch of steel and depth of slab?

0 Answers   RBI,

---

What is the diff. Between rectangle & parallelogram?

10 Answers  

---

How to calculate chejja reinforcement

0 Answers   Grow Homes,

---

How many number of bars used in circular columns? Explain WHY?

5 Answers  

---

What should be the maximum allowable time for placing ready mix concrete? The specification requires concrete placement within 90 minutes of batching at the plant. What is the significance of this 90 minutes & should this be used as a rejection criterion? What effects does the concrete has after that time period?

0 Answers   IOCL,

---