Boiler pumps are an efficient means of moving specific amounts of water from storage into the steam generator, used across a wide range of industries. Boiler feed pumps (BFP) can help provide more accurate and consistent feedwater results, with seven key points worth considering when considering boiler feed pumps as a fundamental. We offers boiler feed pumps from Hoffman Specialty, Mepco, Shipco and Sterling. Boiler feed pumps transport feedwater used to maintain levels in steam boilers or to convert waste water back into steam; typically centrifugal in design and available with various motor sizes for optimal use.
Types of Boiler Feed Pumps
There are various pump types suitable for boiler feed systems. Centrifugal pumps typically provide the highest efficiency performance for standard applications of centrally-operated boilers. Numerous manufacturers specialize in creating boiler feed pumps specifically tailored to modern boiler needs; commonly used models include multi-stage barrel (ideal for high pressure applications) and multi-stage ring section pumps.
Boiler Feed Pump Materials
Prior to the 1950s, most boiler feed pumps (BFPs) were made of unalloyed steels. This limited their discharge pressures as well as flow rates. Over time however, manufacturers adapted their designs by including better materials – most commonly chrome steel for increased durability and corrosion resistance – in their designs; with standards for performance having increased and current BFPs designed to withstand even the strictest heating feed requirements.
Boiler Feed Pump Motors
Electric (asynchronous) motors are commonly employed to power boiler feed pump motors. This enables precise speed controls as well as faster adjustments during operations. Greater levels of control can be attained with variable frequency drive systems (VFD), and steam turbines capable of condensate delivery can even be utilized with specific types of boiler feeds.
Boiler Feed Pump Casings
Understanding the thickness of BFP casings is vital for selecting an appropriate pump. One side must have sufficient wall thickness to meet application pressure loading requirements while other parts must withstand fluctuating temperatures experienced when feeding boilers.
Axial Thrust & Radial Forces
Multi-stage boiler feed pumps use impellers attached to long shafts for an impeller-centric operation, creating an axial thrust which must be balanced for effective operation, along with any radial forces caused by rotating mass. Mechanical imbalance can lead to serious issues during operation of BFPs; proper alignment and maintenance procedures must be observed to guarantee maximum long-term performance.
Boiler Feed Pump Seals
There are various sealing solutions used in boiler feed pumps, including seals made of mechanical material, filling boxes labyrinth seals and floating seals. Each seal performs differently depending on its application.
Thermal Shock & Minimal Flow
One of the biggest threats facing BFPs is thermal shock. This could happen when switching off and on frequently. To prevent thermal shock or destruction to cappings, increase pressure gradually as you warm up. Most boiler feed systems feature an automatic flow limiter or leak off valve that regulates flow accordingly and ensures equipment doesn’t get damaged by this fluctuation in circulation.