Small and Large Scale Vessels
Boiler and Pressure Vessels Quick Links
Small-Scale Laboratory Setups
- Retain all manufacturer's documentation related to the environmental, temperature, and pressure ratings of each component in the system and retain it with other written design specifications for future reference.
- Limit the maximum allowable working pressure, MAWP, and temperature to that of the lowest-rated component in the system.
- Use the minimum size system possible to minimize the amount of stored energy.
- Make sure all components, including soldered or brazed joints, in the system, are rated for the chemical environment(s) to which they will be exposed.
- Use pressure relief devices set at or below the MAWP of the system unless it is impossible to be over-pressurized. A gas regulator is not a pressure relief device.
- Isolate hazardous substances, components, and operations through the use of barricades, shielding, gas cabinets, or remote operation if the consequences of component failure or a process gas leak are unacceptable.
- Do not subject glass equipment to pressure above atmospheric, except specially constructed glassware that is rated for pressure use and that is thoroughly shielded or barricaded on all sides.
Large-Scale Laboratory Setups
In addition to the guidelines for small-scale laboratory setups, follow these requirements for larger-scale vessels:
- All pressure vessels and piping must be constructed, repaired, altered, and tested according to the ASME Boiler and Pressure Vessel Code.
- Protect all pressure equipment by installing pressure-relieving devices that vent to a safe location.
- Set safety or relief valves to activate at a pressure not to exceed the MAWP set for the intended operating temperature. Be sure that all components of the system are rated at or above the MAWP.
- Be sure the capacity of the pressure-relieving device is sufficient to carry off the maximum quantity of liquid or gas that can be generated in or supplied to the attached equipment without permitting a rise in pressure in the vessel to more than 10 percent above the maximum allowable working pressure.
- Take the nature of the vessel's contents into account in the design of pressure-relieving devices.
- Do not install a valve between a safety valve or similar device and the vessel being protected by it.
- Test safety valves at frequent intervals.
- Locate apparatus to be used under pressure only in areas specifically designed for that purpose.
- Do not subject pressure equipment to any pressure exceeding the maximum allowable working pressure as determined by the ASME Boiler and Pressure Vessel Code or as recommended by the manufacturer.
- If pressure equipment is to be used above 650 degrees Fahrenheit, display the maximum allowable working pressure on the apparatus.
- Follow the manufacturer's recommended maintenance and inspection procedure.
Robin McCall-Miller, Occupational Safety Program Manager