Yasser Amer provides a comprehensive comparison of the testing and approval processes for fire protection pumps under these two standards.
Fire protection pumps are critical components in fire safety systems, ensuring the delivery of adequate water supply to suppress fires. The design, testing and approval of these pumps are governed by stringent standards to ensure reliability and performance during emergencies. Two of the most widely recognised standards for fire protection pumps are the Underwriters Laboratories (UL) Standard for Fire Pumps (NFPA-20) and the Loss Prevention Certification Board (LPCB) Standard (EN-12845).
UL Certification
Underwriters Laboratories – founded in 1894 – is a US-American product certifier. Unlike the VdS or the LPCB, their certifications not only extend to the construction, fire protection and safety industries, but rather across a much wider spectrum. This spectrum covers, for example, standards for refrigeration plants, lithium batteries, ice machines, cabling, … . Especially within the American market, where VdS and LPCB are not represented, UL approval is particularly important. However, in the Middle East and the Asia region, UL certification for fire-protection applications plays a major role.
LPCB Certification
The Loss Prevention Certification Board is a part of the BRE (Building Research Establishment) Group. The BRE Group focuses on research, consultancy and testing in the building industry. Among its services are also certifications and acceptances, among others, in the field of fire protection and safety. These certifications under the marking and logo of the LPCB are mostly important in Great Britain, the Middle East and the Asia-Pacific region. Just as with the VdS, the LPCB uses EN and ISO standards as well as its own guidelines as a basis for certification. Meanwhile, there is a cooperation between VdS and the LPCB with the aim of recognising the existing certifications and testing and thus to simplify and to speed up the certification process.
Overview of UL (NFPA-20) and LPCB (EN-12845)
UL (NFPA-20)
The National Fire Protection Association (NFPA) 20 standard, often referred to as UL Fire Pumps, outlines the requirements for the installation of stationary pumps for fire protection. It is widely used in North America and other regions that adopt NFPA standards. NFPA-20 covers the design, performance and testing of fire pumps, including electric motor-driven, diesel engine-driven and steam turbine-driven pumps.
LPCB (EN-12845)
The Loss Prevention Certification Board (LPCB) is a UK-based certification body that provides third-party approval for fire protection products, including fire pumps. The EN-12845 standard, titled “Fixed firefighting systems – Automatic sprinkler systems – Design, installation, and maintenance,” is a European standard that specifies the requirements for fire pumps used in automatic sprinkler systems. LPCB’s LPS 1131 and LPS 1240 standards are specifically tailored for fire pumps and pump sets, aligning with EN-12845.
Key differences in pump selection and design
Hydraulic requirements
NFPA-20 (UL)
- Rated Capacity: Each pump must have a rated capacity as listed in NFPA-20.
- Pressure Limits: The pump’s closed valve pressure must not exceed 140% of the rated pressure.
- Flow and Pressure: The pump must achieve 150% of the rated capacity at not less than 65% of the rated pressure.
- Suction Lift: No suction lift applications are allowed; impellers must be immersed.
- Driver Rating: Pump drivers must be rated to cover the maximum power absorbed by the pump.
- Name-plate Information: The pump duty nameplate must list the rated capacity and rated speed.
EN-12845 (LPCB)
- Stable Pump Curve: The pump curve must be stable, with the head declining as the flow rate increases.
- Driver Power: The pump driver must cater to the maximum pump power absorbed or the power absorbed at the flow rate where the pump’s Net Positive Suction Head Required (NPSHR) equals 16m or the maximum suction static head plus 11m.
- Most Unfavourable Area (MRA): The pump’s rated duty is a function of the most unfavourable area (MRA) in the system.
- Pressure Margin: The pump curve pressure must be at least 0.5 Bar higher than the MRA requirement.
- Flow and Pressure: The pump must supply 140% of the MRA flow at a pressure of not less than 70% of the MRA pressure.
- NPSHR: The pump’s NPSHR at 140% flow must be 1m less than the Net Positive Suction Head Available (NPSHA) at the pump inlet.
Pump curve stability
NFPA-20 (UL)
- NFPA-20 does not explicitly require a stable pump curve, but it mandates that the pump must achieve specific flow and pressure points (e.g., 150% flow at 65% pressure).
- The pump must not exceed 140% of the rated pressure at shutoff.
EN-12845 (LPCB)
- EN-12845 requires a stable pump curve, meaning the head must decline continuously with increasing flow rate. This ensures predictable operation and prevents oscillations or ‘hunting’ between flow rates.
- The pump must not have an unstable curve, as this can lead to unpredictable operating points and potential system failures.
Pump materials and construction
NFPA-20 (UL)
- NFPA-20 does not specify detailed material requirements for pump components but focuses on performance criteria.
- The standard requires that the pump be capable of withstanding the hydraulic and mechanical stresses imposed during operation.
EN-12845 (LPCB)
- EN-12845 specifies material requirements for pump components, including cast iron, cast steel, stainless steel, bronze, or aluminium bronze.
- The pump casing must have a strength of at least 10 Bar, and leakage tests are required to ensure integrity.
Testing and approval processes
UL (NFPA-20) testing and approval
Testing requirements
- Flow and Pressure Tests: The pump must be tested to verify that it meets the rated capacity, pressure, and flow requirements specified in NFPA-20.
- Closed Valve Test: The pump must be tested at closed valve conditions to ensure it does not exceed 140% of the rated pressure.
- NPSH Tests: The pump’s Net Positive Suction Head Required (NPSHR) must be verified to ensure it meets the system’s NPSHA.
- Power Consumption: The pump’s power consumption must be measured to ensure the driver is adequately sized.
Approval process
- Third-Party Certification: UL provides third-party certification for fire pumps, ensuring they meet the requirements of NFPA-20.
- Listing and Labelling: Pumps that pass UL testing are listed and labelled, indicating compliance with NFPA-20.
LPCB (EN-12845) testing and approval
Testing requirements
- Stable Pump Curve: The pump must be tested to ensure the head declines continuously with increasing flow rate.
- Closed Valve Test: The pump must be tested at closed valve conditions to ensure it can operate without failure.
- NPSH Tests: The pump’s NPSHR must be verified, with a requirement that the NPSHR at 140% flow is 1m less than the NPSHA at the pump inlet.
- Power Consumption: The pump’s power consumption must be measured to ensure the driver can handle the maximum power absorbed.
Approval process
- Third-Party Certification: LPCB provides third-party certification for fire pumps, ensuring they meet the requirements of EN-12845 and LPS 1131.
- Listing and Labelling: Pumps that pass LPCB testing are listed and labelled, indicating compliance with EN-12845 and LPS 1131.
Key differences in testing and approval
Stability of pump curve
- NFPA-20: Does not explicitly require a stable pump curve but focuses on specific performance points.
- EN-12845: Requires a stable pump curve to ensure predictable operation and prevent oscillations.
NPSH Requirements
- NFPA-20: Focuses on ensuring the pump’s NPSHR does not exceed the system’s NPSHA.
- EN-12845: Requires the pump’s NPSHR at 140% flow to be 1m less than the NPSHA at the pump inlet.
Material and construction requirements
- NFPA-20: Does not specify detailed material requirements but focuses on performance.
- EN-12845: Specifies material requirements and requires a minimum pump casing strength of 10 Bar.
Third-party certification
- NFPA-20: UL provides third-party certification, ensuring compliance with NFPA-20.
- EN-12845: LPCB provides third-party certification, ensuring compliance with EN-12845 and LPS 1131.
Practical implications for pump selection
Cost considerations
- NFPA-20 (UL): UL-listed pumps are generally more expensive due to the rigorous testing and certification process.
- EN-12845 (LPCB): LPCB-listed pumps may be more cost-effective in regions where EN-12845 is the standard, but they must still meet stringent requirements.
Regional preferences
- NFPA-20 (UL): Widely adopted in North America and other regions that follow NFPA standards.
- EN-12845 (LPCB): Predominantly used in Europe and other regions that follow European standards.
System design
- NFPA-20 (UL): Focuses on achieving specific performance points, making it suitable for systems where precise flow and pressure requirements are critical.
- EN-12845 (LPCB): Emphasises stable pump curves and material requirements, making it suitable for systems where predictable operation and durability are paramount.
Detailed comparison of testing procedures
Flow and pressure testing
NFPA-20 (UL)
- Flow and Pressure Tests: The pump must be tested to verify that it meets the rated capacity, pressure and flow requirements specified in NFPA-20. This includes testing at 100%, 150%, and shutoff conditions.
- Closed Valve Test: The pump must be tested at closed valve conditions to ensure it does not exceed 140% of the rated pressure. This test is crucial to verify that the pump can handle the maximum pressure without failure.
EN-12845 (LPCB)
- Stable Pump Curve: The pump must be tested to ensure the head declines continuously with increasing flow rate. This is a critical requirement to ensure the pump operates predictably under varying flow conditions.
- Closed Valve Test: The pump must be tested at closed valve conditions to ensure it can operate without failure. This test is similar to NFPA-20 but emphasises the importance of stable operation under no-flow conditions.
NPSH testing
NFPA-20 (UL)
- NPSH Tests: The pump’s Net Positive Suction Head Required (NPSHR) must be verified to ensure it meets the system’s NPSHA. This is crucial to prevent cavitation, which can damage the pump and reduce its efficiency.
EN-12845 (LPCB)
- NPSH Tests: The pump’s NPSHR must be verified, with a requirement that the NPSHR at 140% flow is 1m less than the NPSHA at the pump inlet. This ensures that the pump can handle the increased flow without cavitation.
Power consumption testing
NFPA-20 (UL)
- Power Consumption: The pump’s power consumption must be measured to ensure the driver is adequately sized. This is important to prevent overloading the driver and ensure reliable operation.
EN-12845 (LPCB)
- Power Consumption: The pump’s power consumption must be measured to ensure the driver can handle the maximum power absorbed. This is similar to NFPA-20 but includes additional requirements for pumps with rising power characteristic curves.
Detailed comparison of approval processes
Third-party certification
NFPA-20 (UL)
- Third-Party Certification: UL provides third-party certification for fire pumps, ensuring they meet the requirements of NFPA-20. This includes rigorous testing and inspection to verify compliance.
- Listing and Labelling: Pumps that pass UL testing are listed and labelled, indicating compliance with NFPA-20. This provides assurance to end-users that the pump meets the required standards.
EN-12845 (LPCB)
- Third-Party Certification: LPCB provides third-party certification for fire pumps, ensuring they meet the requirements of EN-12845 and LPS 1131. This includes testing and inspection to verify compliance with the standard.
- Listing and Labelling: Pumps that pass LPCB testing are listed and labelled, indicating compliance with EN-12845 and LPS 1131. This provides assurance to end-users that the pump meets the required standards.
Documentation and marking
NFPA-20 (UL)
- Nameplate Information: The pump duty nameplate must list the rated capacity and rated speed. This provides essential information for installation and operation.
- Documentation: Detailed documentation, including test reports and installation instructions, must be provided to ensure proper installation and maintenance.
EN-12845 (LPCB)
- Nameplate Information: The pump must have a securely fitted nameplate that includes the supplier’s name, model designation, serial number, year of manufacture and LPCB approval mark. This provides essential information for installation and operation.
- Documentation: Detailed documentation, including test reports, installation instructions, and maintenance manuals, must be provided to ensure proper installation and maintenance.
Practical implications for pump selection
Cost considerations
- NFPA-20 (UL): UL-listed pumps are generally more expensive due to the rigorous testing and certification process. However, this cost is often justified by the assurance of quality and reliability.
- EN-12845 (LPCB): LPCB-listed pumps may be more cost-effective in regions where EN-12845 is the standard, but they must still meet stringent requirements. The cost savings may be offset by the need for additional testing and certification.
Regional preferences
- NFPA-20 (UL): Widely adopted in North America and other regions that follow NFPA standards. This makes UL-listed pumps the preferred choice in these regions.
- EN-12845 (LPCB): Predominantly used in Europe and other regions that follow European standards. This makes LPCB-listed pumps the preferred choice in these regions.
System design
- NFPA-20 (UL): Focuses on achieving specific performance points, making it suitable for systems where precise flow and pressure requirements are critical. This is particularly important in high-rise buildings and industrial facilities.
- EN-12845 (LPCB): Emphasises stable pump curves and material requirements, making it suitable for systems where predictable operation and durability are paramount. This is particularly important in high-hazard environments and critical infrastructure.
Conclusion
The testing and approval processes for fire protection pumps under UL (NFPA-20) and LPCB (EN-12845) standards have distinct differences in terms of hydraulic requirements, pump curve stability, material specifications, and testing procedures. While NFPA-20 focuses on achieving specific performance points and is widely adopted in North America, EN-12845 emphasises stable pump curves and material requirements, making it the preferred standard in Europe. Both standards ensure the reliability and performance of fire protection pumps, but the choice between them depends on regional preferences, system design requirements and cost considerations.
Understanding these differences is crucial for engineers, designers and fire safety professionals when selecting and specifying fire protection pumps for their systems. By adhering to the appropriate standard, they can ensure that the pumps will perform reliably in the event of a fire, ultimately protecting lives and property.
