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[Art Montemayor]

ahboon:

You left out the following design criteria:

1. SAFETY. I consider safety the most important criteria and the primary concern in any engineer's design. I classify it as the number one issue and I place environmental concerns under Safety. Issues such as personnel protection (i.e. insulation, handrails, ladders, platforms, lighting, etc) should always be of concern in materials of construction, operability, and mechanical design. Equipment and process Fire Protection is included here. Proper over-pressurization protection should be done, complete with PSV calculations and piping according to code(s). All the possible, credible over-pressurization scenarios, including the Fire scenario, must be considered and designed for. Safety alarms and interlocks should be clearly explained and pointed out. Electrical classification areas should be identified and listed.

2. Economics. Capital and Operating Costs should also be a design issue. Factors such as considering standard, seamless pipe as cylindrical vessel components together with standard ellipsoidal heads are more economical and practical instead of rolling a steel plate, seam-welding it, and using a welded hemispherical head. Sometimes stainless or fiberglass material on items such as platform grating and ladders will save valuable process downtime and production product when corrosion repairs are considered.

3. Insulation. Insulate equipment according to heat conservation (Economic) and personnel protection needs (Safety).

4. Equipment location and orientation. Locate and place equipment in safe, accessible and operable location.

5. Equipment protection. Prime, paint, and protect equipment from environmental and process corrosion. Be sure to include corrosion allowance on Specification Sheets when specifying all equipment.

I hope this helps you understand what a Process and a Project Engineer must consider while designing and constructing process equipment.

Art Montemayor
Spring, TX