Masdaf – YNM NFPA fire pump in accordance with NFPA 20

The YNM NFPA fire pump is a single-stage, end-suction centrifugal pump designed by Masdaf in accordance with the NFPA 20 standard. The series has a flow rate of 11 to 227 m³/h, a head of 30 to 140 m, and a speed of 3,000 to 3,600 rpm. The pump operates with water at temperatures ranging from 0 to 60 °C and is available with either an electric or diesel drive.

What are the benefits of compliance with NFPA 20?

NFPA 20 is the American standard for fixed fire-fighting pumps. It describes not only the pump itself, but also the requirements for its installation, power supply, control and testing. A designer commissioning a system to this standard must select equipment whose design complies with it — otherwise, the system will not pass acceptance testing. For the YNM NFPA, this means, in particular, sealing the shaft with soft gland packing: controlled drip leakage along the shaft is standard for a fire pump, as this is what cools and lubricates the packing during the infrequent full-load starts.

How the YNM pump works

The rotor consists of a rigid shaft mounted on grease-lubricated bearings and a sealed impeller, fitted within a removable bearing assembly. The assembly is connected to a spiral casing with axial suction, fitted with wear rings. The entire rotating assembly can be removed from the casing for maintenance without disconnecting the pipework; a remote coupling can be fitted on request, allowing the rotor to be removed without dismantling the motor. The pump and drive are mounted on a common frame and connected by a flexible coupling, selected to suit the unit’s power and operating conditions.

Technical specifications for the YNM NFPA

We tailor the material of the flow path, the motor power and the operating point to the specific order, based on the standard size curve.

 When should you choose YNM NFPA, and when should you choose YNM UL/FM?

The hydraulic design is identical in both series — end-suction, spiral casing, gland seal. The only difference lies in the regulatory framework, which determines the price and delivery time. The YNM NFPA is manufactured to the NFPA 20 standard. The YNM UL/FM also has UL 448 and FM 1319 approvals, along with corresponding approvals for the motor, diesel engine and control cabinet. If the design brief or the insurer’s requirements specify UL/FM, the NFPA 20 version will not pass acceptance testing. If, however, the requirement is limited to NFPA 20, UL/FM approvals will simply result in an unnecessary extra cost. The ranges also differ: the YNM NFPA covers lower flow rates from 11 m³/h and pipe sizes from DN 50, whilst the YNM UL/FM starts with larger sizes.

Where are YNM NFPA pumps used?

The manufacturer specifies the scope of application for this series as fire-extinguishing systems for low, medium and high-risk environments. The flow rate range of 11–227 m³/h covers most sprinkler and valve-based systems in medium-sized buildings.

Selection, supply and service from Steiner Ukraine

Errors in the selection of a fire pump are usually only detected not during installation, but at the system acceptance stage; therefore, Steiner Ukraine begins its calculations based on the standard under which the facility is to be commissioned. To select a YNM NFPA pump, the following are required: the acceptance standard, the design flow rate and pressure at the control point, the available suction head, the drive type and the power supply redundancy requirements. Based on this data, we determine the model and size, agree on the unit’s configuration and provide a specification with certificates. Routine maintenance for this series — re-packing the gland and lubricating the bearings — is described in the manufacturer’s manual and is carried out without dismantling the unit.