Production lines depend heavily on efficient and reliable boiler operation. This is why Grundfos' robust feeding pumps for steam boilers, hot water boilers and thermal oil boilers have been specially designed to offer optimum performance in even the most extreme conditions.

All Grundfos feeding pumps can be fitted with an integrated frequency converter to optimize processes in terms of temperature, pressure level and quality of steam. If make-up of the water is part of the process, dosing pumps will ensure highly accurate dosing of any additive.

When it comes to feeding pumps, steam boilers are among the harshest and most challenging applications. The process involves high pressure, high ambient temperatures and a significant number of starts and stops that stress the pump. To accommodate the extreme conditions, Grundfos' multistage feeding pumps have been optimized in every aspect and are even capable of efficiently handling poor inlet conditions. The pumps can further be supplied with an air-cooled top that protects the shaft from any damage caused by the high temperatures – and with a monitor that will supervise the process and warn you about any deviances.

DUPLEX (PUMP) A DESIGNATION OF A RECIPROCATING PUMP THAT USES TWO DRIVE RODS.

Duplex pumps are common in both single and dual acting designs. Due to some of the benefits over simplex pumps, and simpler design than other reciprocating pumps, they are often a preferred pump for many applications. 

Essentially, a single action duplex pump is two simplex pumps running at 180 degrees from each other. As one plunger or piston is pumping fluid into the outlet port, the other is drawing in from the inlet. A dual action is similar in style but is only offset at 90 degrees. Theoretically, a dual action duplex operates using four single-acting plungers or pistons. Keeping the rotation at 180 degrees would create two overlapping sets of plungers or pistons. A 90-degree offset helps to stabilize the flow. See the flow characteristics below for more information.

Note that the dual action charts are made specifically for a plunger pump. In a dual action piston pump, pump chambers one and three would look similar to that shown above, but chambers two and four would have a slightly lower relative velocity. This is due to the fact that one side of the piston requires the drive rod, reducing the usable volume within these pump chambers.

DUPLEX PUMP EXAMPLE APPLICATIONS

Duplex pumps are used in low flow applications across many industries.

The basic CR pump range, which applies to almost any industrial solution, is in itself the broadest range available. With our modular approach, we have made it even broader.

The basic CR pump range is available as standard in three different materials including two grades of stainless steel, and all-titanium versions in eleven flow sizes, capable of producing up to 40 bars of pressure, and with a variety of shaft seals, rubbers, supply voltages and frequencies.

These pump parts, typically vulnerable to difficult liquids or particularly demanding operating conditions, have been optimized to the task and designed for specific requirements.

FEATURES & BENEFITS

• Reliability
• High efficiency
• Service-friendly
• Space-saving
• Suitable for slightly aggressive liquids
• High corrosion resistance
• Single pump solution enabling high pressure