I don't believe the exceptions in non-mandatory appendix M apply to the configuration you describe. Before you go down this path I recommend you read paragraphs UG-125 & UG-140 of ASME section VIII. UG-125 states that all PV regardless of size under the scope of the division shall have...
I recommend your consider a condensing boiler, they can achieve high efficiencies. These units operate with the flue gas below the acid dew point, corrosion resistant materials are used throughout the combustion and exhaust sections.
Using RO/DI water as your feed-water source should all but eliminate any chemical cleaning requirement. Are you chemically cleaning based on a predetermined frequency or a condition assessment (the presence of mineral scale)? I would not recommend perfoming a cleaning procedure unless there are...
The ASTM A-181 specification is a standard for carbon steel forgings general purpose piping. Are you sure that is the correct specification for the flange material in question?
Javier:
An organizatrion with an R stamp should be capable of performing the welding required to install the new valves in place, but not any adjustments or calibration of the new valves, this would require VR certification. I recommend you consult with the valve manufacturer, they may...
Mab:
I have not had to re-enforce any doors. If you are concerned that the door may not be able to take the force required to achieve the necessary compression for the spiral wound gasket material, there are some other wire impregnated graphite gasket materials that may meet your needs, grafoil...
Seat taper and seating area overlap are important dimension on that design may-way. If you have or could obtain the original drawings with the man-way seat and door dimension that would be helpfult to determine if excessive seat taper is the cause of your problems. Ensuring that the door is...
Champion:
The RVI would be during the next outage, that is why I stated soonest available opportunity. High boiler water chloride levels increase the propensity for carry-over, not scale formation; choride ions are inversely soluble. Typically at that low of a chloride level, carry-over is not...
Another option for level monitoring and control:
http://www.vegacontrols.co.uk/vegapuls_radar_index.asp?fixedRangeID=01
For pH monitoring, you may have to draw a small continous samle from the process and cool it before sending it to the probe.
Champion:
What do you mean by the term "off spec"? Was there actual contamination of the feed-water with scale forming minerals, or were the residual treatment levels in the boiler-water out of the desired control range by 10%?
Do your operators test for either turbidity, total dissolved solids...
Rather than purchasing this specialized equipment for limited use, have you considered using an existing testing facility that meets your requirements?
The organization I used to work for has a steam testing facility in Philadelphia that may meet your needs. I know they've performed testing for...
Are there any steam purity requirements for the process, will it have to be superheated? If there is, it may make you available selection pool even even more narrow. I've used small oil/gas fired forced flow steam generators (Vapor & Clayton) along with an accumulator for PRV testing in the...