access openings

[lcatg]

Hi,

What is the meaning of access opening as given in UG-45? How different its from other nozzles?

In a annealing furnace, a 6" nozzle is given to provide power connection from transformer to the heating element through feedthroughs. Is this nozzle a access opening?
The furnace is double walled and in the annular space water flows.Inlet and outlet connections are given using 1" BSP Nozzles.This nozzle is designed as per UG-45. Is that 6" nozzle a acces opening?
what exactly is the difference between access and other type openings?

 

[pennpiper]

Depending on the size of a Vessel "Access Openings" are normally provided in the Skirt of a Vessel for Inspection, Maintenance and Safety.
In the Skirt of all Vessel Please provide Access Openings Per the following:
- Vessels smaller than 2'-0" shall be fitted with Hand Holes only
- Vessels 2'-0" to 6'-0" in diameter provide one (1) Access Opening located for clear approach for Maintenance and Safety
- Vessels 6'-0" to 15'-0" in diameter provide a minimum of two (2) Access Openings, one located for clear approach for Maintenance and Safety, the other shall be located 180 degrees opposite for cross air flow. If more than two are provided locate them equally spaced around the Vessel Skirt.

Hand Holes (Access Opening) are only large enough to reach in with your arm.

Access Openings which allow for full entry may be 24" to 30" wide by 48" to 72" high which will a worker in full winter dress to climb inside the Skirt. Access to the inside of a Skirt of an Operation should never be allowed or done until the inside of the skirt is tested and cleared for safe work.

Note: Vessels on Legs do not require Access Openings.

Sometimes its possible to do all the right things and still get bad results

 

[bpv66]

Access or Inspection Openings are explained in detail in UG-46 of ASME Section VIII, Div. 1. Inspection openings do not require tb1, tb2, and tb3 calculations specified in UG-45 since they are not nozzles. The size of the inspection openings are based on the diameter of the vessel which you did not mention in your post.

 

[doct9960]

lingeshgdvg,

There's an ASME interpretation that seem similar to your case...

Interpretation: VIII-1-83-185
Subject: Section VIII, Division 1; UG-45
Date Issued: November 10, 1983
File: BC83-317

Question: Openings for NPS I through NPS 2 1/2 are used for heater wells and are subjected to external pressure only. A small portion of these wells (approximately 1/2 in. to 3 in.) extends into the atmosphere for insertion of heater elements. May these openings be considered access openings when using the provisions of UG-45 in Section VIII, Division 1?

Reply: No