ASME I Flanged-In Manhole
ASME I Flanged-In Manhole
(OP)
Please, verify if my interpretation of the code is correct:
In the case of a elliptical (12x16in) flanged-in opening in a elliptical 24in head we have two options:
1- Flued opening such as indicated in Fig. UG-38;
2- Opening with ring such as Fig. PG-28.
In the first case, the thickness of the head should be computed using the equation in PG-29.1. Since it's a flued opening, the additional thickness specified in PG-29.3 is not required. Also, area reinforcement calculation is not required for configuration according to PG-34.2.
In the second case, the thickness of the head should also be calculated according to equation in PG-29.1 and the additional thickness according to PG-29.3 is required. In this case, area reinforcement calculation is also required.
In the case of a elliptical (12x16in) flanged-in opening in a elliptical 24in head we have two options:
1- Flued opening such as indicated in Fig. UG-38;
2- Opening with ring such as Fig. PG-28.
In the first case, the thickness of the head should be computed using the equation in PG-29.1. Since it's a flued opening, the additional thickness specified in PG-29.3 is not required. Also, area reinforcement calculation is not required for configuration according to PG-34.2.
In the second case, the thickness of the head should also be calculated according to equation in PG-29.1 and the additional thickness according to PG-29.3 is required. In this case, area reinforcement calculation is also required.





RE: ASME I Flanged-In Manhole
RE: ASME I Flanged-In Manhole
About the interpretation, do you think that's correct?
RE: ASME I Flanged-In Manhole
The manhole can be fabricated in two ways: with a flanged-in or with a welded ring.
In the case of a flanged-in, the head should be calculated according to the second part of PG-29.7 and the thickness shall be increased according to PG-29.3. No area reinforcement calculation is required and the criteria related to the flange in PG-34.2 apply.
In the case of a welded ring, area reinforcement calculation is required and PG-28 apply. However, it seems to me that the head thickness should be calculated normally according to the first part of PG-29.7 and increase in thickness is NOT required.
What do you think?
Another question is: what is "flanged opening supported by an attached flue" written in PG-29.3?
Best regards.
RE: ASME I Flanged-In Manhole
After thoughting a little over this issue again, I came out with another interpretation.
The manhole can be fabricated in two ways: with a flanged-in or with a welded ring.
In the case of a flanged-in, the head should be calculated according to the second part of PG-29.7 and the thickness shall be increased according to PG-29.3. No area reinforcement calculation is required and the criteria related to the flange in PG-34.2 apply.
In the case of a welded ring, area reinforcement calculation is required and PG-28 apply. Additionally, increase in thickness is also required.
What do you think?
Another question is: what is "flanged opening supported by an attached flue" written in PG-29.3?
Best regards.
RE: ASME I Flanged-In Manhole
nothing wrong with it if you have the machinery to make it and it will save you in welding and reinforcings.
2- flanged with flue opening is a different thing, you flange- in and then
install your tube/pipe ''flue'' or even a manhole ring or handhole.
3-you may weld the manhole and reinforce as required. not always the plate has to be thicker.
4-why to blame the customer!
RE: ASME I Flanged-In Manhole
Do you have any picture and/or drawing showing the difference between the flue and the flanged-in opening?
You say that not always the plate has to be thicker. What do you mean by not always? What are the conditions that you refer?
Best regards.
RE: ASME I Flanged-In Manhole
i am sorry but my teachings are very conservative, requires a lot of home work.
Flues have nothing to do with manhole or handholes,
it is just form of atatching. a sample flanged flue are the cheap water heaters tank type 30 thru 50 GL capacity.in the US American standard water heaters and others sold at home-depot.