They are allowed. Most O-lets are self reinforcing connections, and they are used widely on PVs. 2"NPS and under they do not require calcualtions as the drill size opening is to small as per UG-40 something.
Theres afew private organizations around that offer training for this exam.
BI&I is the one i would recommend as they teach it very well and have a good success rate with candiates passing it.
You can also contact the National Board themselves and sign up for the 2 week pre commision course...
Hehe pretty good points, but lets make this easy for all of you.
PWHT applys only to items that have been WELDED
Stress Relief applys to all items. (ie Mechaincal Stress, Heat Stress, etc etc.)
Codes of Construction apply these in different ways.
Depends on the pressure of the boiler and your jurisdictions thoughts on modifying fittings.
If your boiler is over 15psi (IE Power Boiler) then the rules in ASME Sec I apply. It says in there that u must have a stop valve between the steam and any instumentation/tubing line attached.
Chances...