Canadian Registered Safety Technician (CRST)

Correct: Rotary gas meters are precision instruments with tight internal tolerances. Excessive vibration from heavy machinery like turbines can cause bearing failure, rotor misalignment, or catastrophic mechanical damage, leading to gas leaks or inaccurate billing. Gas installation codes and manufacturer guidelines specifically require that meters be protected from vibration, which is best achieved through physical isolation or the use of dampening mounts.

Incorrect: Increasing inspection frequency does not address the underlying mechanical stress or the regulatory non-compliance regarding installation environment. Sediment traps are designed to remove particulates from the gas stream and have no effect on external mechanical vibration. Diaphragm meters are also sensitive to vibration and may not be suitable for the high-volume flow requirements of an industrial auxiliary power system, making replacement a poor technical solution compared to proper mounting.

Takeaway: Gas meters must be installed in locations protected from excessive vibration to ensure mechanical longevity, safety, and measurement accuracy.

Correct: Rotary gas meters are precision instruments that require specific mounting orientations to ensure that the internal oil reservoirs correctly lubricate the timing gears and bearings. Deviating from manufacturer specifications constitutes a failure of internal safety controls and risks mechanical failure or gas leaks, which the audit function must prevent regardless of project timelines or space constraints.

Correct: In gas meter installation, regulatory compliance and safety are paramount. The CSA B149.1 Natural Gas and Propane Installation Code requires specific clearances between gas regulators/relief devices and building openings or ignition sources (such as electrical meters or air intakes). Ensuring these clearances are met prevents hazardous gas accumulation or accidental ignition, making it the highest priority during installation or when a site-specific problem is identified.

Incorrect: Increasing pipe size is a design consideration for flow and pressure drop but does not address the safety hazards associated with improper meter placement. Applying corrosion-resistant paint is a maintenance practice that does not override the fundamental safety requirements of the gas code. While bypass valves are beneficial for system serviceability and continuous operation, they are secondary to the immediate safety requirement of maintaining proper clearances from potential hazards.

Takeaway: The primary regulatory priority for gas meter installation is ensuring the discharge and meter location maintain mandatory safety clearances from ignition sources and building openings.

Correct: Rotary gas meters are positive displacement meters with extremely tight tolerances between the rotating impellers and the meter housing. Because of these precision clearances, even small amounts of debris such as pipe scale, weld slag, or dirt can cause the impellers to jam or become damaged. Installing an upstream strainer or filter is a mandatory practice to protect the internal components of a rotary meter from such mechanical failure.

Incorrect: Providing specific lengths of straight pipe is a requirement for turbine-type meters to ensure a uniform velocity profile, but it is not a primary requirement for the mechanical protection of rotary meters. While orientation is important for lubrication, many modern rotary meters are designed to be mounted in either horizontal or vertical planes as long as the oil reservoirs are adjusted accordingly; therefore, a ‘horizontal only’ rule is incorrect. A secondary regulator downstream does not protect the meter’s internal impellers from the debris mentioned in the audit report.

Takeaway: Rotary gas meters require upstream filtration to protect precision-machined internal impellers from damage caused by piping debris and contaminants.

Correct: Rotary gas meters are precision-machined instruments that are highly susceptible to damage from external mechanical forces. In a risk assessment, ensuring that the meter is not subjected to piping strain (due to misalignment) or excessive vibration is critical. Mechanical stress can distort the meter housing, leading to internal rotor contact or seal failure, which poses a significant safety risk in energy recovery systems.

Incorrect: Increasing pipe diameter to reduce velocity is a design consideration for flow capacity but does not address the immediate risk of physical stress on the meter housing. Installing a pressure relief valve is a general safety requirement for pressurized systems but does not mitigate the specific risk of mechanical strain from poor installation. Changing the lubricant is a maintenance procedure that does not resolve structural or alignment issues identified during a risk assessment.

Takeaway: Proper alignment and vibration-free support are essential for the structural integrity and safe operation of rotary gas meters in industrial energy systems.

Correct: In industrial applications, particularly those involving rotary or turbine meters where the facility requires a continuous supply of gas, a bypass is required. This allows the meter to be isolated for periodic proving (accuracy testing), maintenance, or replacement without shutting down the downstream equipment, which is critical for 24/7 industrial operations.

Incorrect: Providing a secondary flow path to mitigate pressure drops is a design issue related to pipe sizing and meter capacity, not the purpose of a bypass. A bypass is not intended to serve as a redundant safety shut-off path; safety shut-offs are separate components like solenoid valves or emergency shutdown valves. Manual temperature compensation adjustments are typically handled by the meter’s internal mechanical or electronic compensator and do not require a bypass for the adjustment process itself.

Takeaway: Industrial gas meter bypasses are essential for ensuring operational continuity during required meter maintenance, testing, or replacement in continuous-flow environments.

Correct: In gas fitting and auditing, a bypass valve on a meter set must be closed and sealed during normal operation. Its purpose is to facilitate maintenance without interrupting service, not to supplement flow. If the system experiences pressure drops that trip low-pressure switches, the underlying issue is likely an undersized regulator or piping, not a need to bypass the meter. Leaving a bypass open results in unmeasured gas, which is a significant financial and safety control failure.

Incorrect: Documenting a bypass as a standard operating procedure is a violation of safety codes and utility regulations regarding unmeasured gas and system integrity. Diaphragm meters are generally less suited for high-volume industrial loads than rotary meters, and replacing the meter type does not justify the use of a bypass for flow supplementation. Installing a check valve on a bypass line is not a recognized solution for pressure drop issues and fails to address the requirement that all gas must be measured by the meter during normal operation.

Takeaway: Bypass valves on gas meter installations must remain closed and sealed to ensure accurate measurement and to maintain the integrity of the pressure regulation system.

Correct: Rotary gas meters operate with extremely tight tolerances between the rotating impellers and the meter housing. Any solid debris, such as pipe scale, welding slag, or dirt, can easily jam or damage the impellers. Therefore, installing a strainer or filter immediately upstream is a critical requirement to ensure the mechanical integrity and accuracy of the meter.

Incorrect: Installing the meter at the lowest point of the system is incorrect because it would cause the meter to act as a trap for moisture and debris, increasing the risk of damage. A bypass line is used for maintenance purposes but does not protect the meter from debris during normal operation. Increasing the pipe size to reduce velocity does not address the physical presence of particulates that can cause mechanical seizure in a rotary meter.

Takeaway: Upstream filtration is essential for protecting the precision internal components of rotary gas meters from mechanical failure caused by debris.

Correct: Diaphragm meters are highly sensitive to pressure pulsations and harmonic resonance, which can lead to inaccurate readings and premature mechanical failure of the internal components. Installing a surge chamber or a restrictive orifice acts as a dampener, smoothing out the flow and protecting the meter’s delicate diaphragm and linkage assembly from the stresses of non-steady flow.

Incorrect: Turbine meters are even more susceptible to damage and measurement errors from pulsations than diaphragm meters, as the fluctuations can cause the turbine wheel to over-speed or experience bearing fatigue. Increasing the inlet pressure does not address the underlying cause of harmonic resonance and may exceed the meter’s rated capacity. A bypass loop is intended for maintenance and does not solve the operational issue of vibration during active gas consumption.

Takeaway: Protecting gas meters from downstream pressure pulsations through dampening devices is essential for maintaining measurement accuracy and preventing mechanical failure.

Correct: According to gas installation codes and safety standards, gas meters and regulators must be protected from physical damage. In a commercial setting with vehicle traffic, such as a shipping bay, the meter is at high risk of being struck. Therefore, the meter must either be located in a safe area or be provided with substantial physical protection, such as bollards, to ensure the integrity of the gas system.

Incorrect: While minimizing the length of piping and ensuring proper ventilation are valid considerations in gas fitting, they do not override the fundamental safety requirement to protect the meter from mechanical impact. Static electricity is generally managed through proper grounding and bonding of the piping system rather than meter placement relative to foot or vehicle traffic.

Takeaway: Gas meters must be strategically located or physically shielded to prevent mechanical damage from vehicles and equipment in high-traffic areas.