In an earlier post tonight, I shared an OSHA Hazard Bulletin from 1993 titled: Chemical Exposures from Industrial Valve and Piping Systems. In that Bulletin OSHA, talks about the hazards and accidents related to workers opening processes. But there is another serious error we see often… Open Ended Piping. This is a serious NO-NO in hazardous materials processes. Although OSHA does not have a specific requirement against this hazard and ASME B31 series makes no mention of this unsafe practice, we have always used EPA rules for Treatment, Storage, and Disposal (TSD) facilities. In fact, EPA made this requirement for TSD facilties after a tragic accident at a TSD in the early 1990’s. Here is what EPA requires, and it is somthing every business that processes hazardous materials should adopt:
§ 264.1056 Standards: Open-ended valves or lines.
(a)
(1) Each open-ended valve or line shall be equipped with a cap, blind flange, plug, or a second valve.
(2) The cap, blind flange, plug, or second valve shall seal the open end at all times except during operations requiring hazardous waste stream flow through the open-ended valve or line.
(b) Each open-ended valve or line equipped with a second valve shall be operated in a manner such that the valve on the hazardous waste stream end is closed before the second valve is closed.
(c) When a double block and bleed system is being used, the bleed valve or line may remain open during operations that require venting the line between the block valves but shall comply with paragraph (a) of this section at all other times.
§ 60.482-6a Standards: Open-ended valves or lines.
(a)
(1) Each open-ended valve or line shall be equipped with a cap, blind flange, plug, or a second valve, except as provided in § 60.482-1a(c) and paragraphs (d) and (e) of this section.
(2) The cap, blind flange, plug, or second valve shall seal the open end at all times except during operations requiring process fluid flow through the open-ended valve or line.
(b) Each open-ended valve or line equipped with a second valve shall be operated in a manner such that the valve on the process fluid end is closed before the second valve is closed.
(c) When a double block-and-bleed system is being used, the bleed valve or line may remain open during operations that require venting the line between the block valves but shall comply with paragraph (a) of this section at all other times.
(d) Open-ended valves or lines in an emergency shutdown system which are designed to open automatically in the event of a process upset are exempt from the requirements of paragraphs (a), (b), and (c) of this section.
(e) Open-ended valves or lines containing materials which would autocatalytically polymerize or would present an explosion, serious overpressure, or other safety hazard if capped or equipped with a double block and bleed system as specified in paragraphs (a) through (c) of this section are exempt from the requirements of paragraphs (a) through (c) of this section.
Source: https://www.ecfr.gov/current/title-40/chapter-I/subchapter-I/part-264/subpart-BB/section-264.1056