Inspection tips

Preparing a boiler for an internal inspection can be nerve-wracking. Here are some general tips to keep in mind. If you have any additional questions, please contact your state's boiler inspection office.

How to prepare for an internal boiler inspection

This document gives you basic guidelines on how to prepare a boiler for an internal boiler inspection. Internal boiler inspections are often requested by inspectors so that they can view the water and fire sides of the boiler and gage the level of scale, corrosion, or damage to the boiler. Internal boiler inspections are very critical in large boilers with open loop systems.

The inspector is the ultimate resource for preparation efforts, so please use this document as a general guide only (it is meant to advise only). If you have questions or concerns, please bring those up to your inspector prior to the boiler inspection.

Responsibility of Safety During Internal Boiler Inspection:

The owner-user and Inspector shall determine that the pressure retaining items may be entered safely. This shall include:

  • Potential hazards associated with entry into the object have been identified by the owner-user and are brought to the attention of the Inspector, along with acceptable means or methods for dealing with each of these hazards;
  • Coordination of entry into the object by the Inspector and an owner-user representative(s) working in or near the object;
  • If personal protective equipment is required to enter an object, the necessary equipment is available, and the Inspector is properly trained in its use;
  • An effective energy isolation program is in place and in effect that will prevent the unexpected energizing, start up or release of stored energy (lock out and/or tag out will open in new window);
  • All applicable safety regulations are otherwise being followed. This includes applicable governmental, state, regional, and/or local rules and regulations. The owner-user programs or the Inspectors’ employers’ safety programs or similar regulations also apply. In the absence of such rules, prudent and generally accepted engineering safety procedures satisfactory to the Inspector shall be employed by the owner-user.

Preparation for Internal Boiler Inspection:

  • When a boiler is to be prepared for internal boiler inspection, the water should not be withdrawn until the setting has been sufficiently cooled at a rate to avoid damage to the boiler.
  • The owner or user should prepare a boiler for internal boiler inspection in the following manner:
    • The fuel supply and ignition system shall be locked out and/or tagged out, in accordance with the owner-user’s procedures.
    • Water shall be withdrawn and the waterside thoroughly washed.
    • Manhole and hand-hole plates, washout plugs, as well as boiler inspection plugs in water column connections shall be removed as required by the Inspector. The boiler shall be cooled and thoroughly cleaned.
    • Any leakage of steam or hot water into the boiler shall be prevented by disconnecting the pipe or valve at the most convenient point or any appropriate means approved by the Inspector.
    • Before opening the manhole(s) and entering any part of a boiler which is connected to a common header with other boilers, the required steam or water system stop valves (including bypass) must be closed, locked out and/or tagged out in accordance with the owner-user’s procedures, and drain valves or cocks between the two closed stop valves opened. After draining the boiler, the blow-off valves shall be closed, locked out and/or tagged out in accordance with the owner-user’s procedures. Alternatively, lines may be blanked or sections of pipe removed. Blow-off lines, where practicable, shall be disconnected between pressure parts and valves. All drains and vent lines shall be open.
  • The Inspector shall not enter a boiler before all safety precautions listed above have been taken. The Inspector shall ensure that all free blow vent or drain valves are open. The temperature of the boiler shall be such that the inspecting personnel will not be exposed to excessive heat.
  • The Inspector shall be satisfied that a safe atmosphere exists before entering either the fireside or waterside of a boiler. The Inspector shall not be permitted to enter an area containing toxic, flammable or inert gases, vapors or dust without appropriate personal protective equipment. The oxygen content of the breath-able atmosphere shall be between 19.5% and 23.5%.
  • Personal protective equipment and clothing must be worn as appropriate. This may include, among other items, protective outer clothing, gloves, eye protection, and foot protection. The Inspector shall have the proper training governing the selection and use of any personal protective equipment necessary to safely perform each boiler inspection. Particular attention shall be afforded respiratory protection if the testing of the atmosphere of the object reveals any of the hazards noted in the paragraph above.
  • If requested by the Inspector or required by regulation or applicable procedure, a responsible person (“attendant”) shall remain outside the boiler at the point of entry while the Inspector is inside and shall monitor activity inside and outside and communicate with the Inspector as necessary. The attendant shall have a means of summoning rescue assistance if needed and to facilitate rescue procedures for those inside the boiler without personally entering the boiler.