TB Mag Series Mag-Drive Pumps At York Fluid Controls

TB Mag Series Mag-Drive Pumps

So what makes the TB-mag series mag-drive pumps so much better than the competition? Thrust Balancing and Engineering Design. The TB-mag (short for Thrust Balanced mag-drive) is the most revolutionary engineering concept to enter the mag-drive market since the invention of the mag-drive pump itself. The patent pending thrust balance technology behind the TB-mag series completely eliminates axial thrust bearings and provides the basis for a controlled internal environment. Superior engineering design minimizes the issue of secondary containment by providing secondary bearings. No other product on the market today offers these features at such a cost-effective and cost-competitive price. In short, the TB-mag series mag-drive pumps sets new standards for non-metallic sealless pumps in application of use, product durability and customer driven value.

The Value of Thrust Balancing & Engineering...

Thrust Balancing technology provides a controlled environment for the processlubricated bearings. Internal pressures of the pump are regulated in such a manner that the pressures in the bearing area always remain high, virtually eliminating the possibility of flashing. This is a major advantage for bearing health and pump life. Engineering design of the wear ring area provides particulate control resulting in a “clean stream” to the bearings, further enhancing bearing life. Downstream of the bearings, the still cool liquid is directed into the suction where it mixes with the main flow. Such process control allows the TB-mag series mag-drive pumps to handle Volatile liquids safely and produce B.E.P.’s equivalent to sealed pumps. No other non-metallic sealless pump offers these features.

Features And Bennefits

The TB-mag series mag-drive pumps provides the user with the most advanced non-metallic mag-drive technology available today.

Thrust balanced impeller eliminates axial bearing problems during low suction pressure operation. The thrust balancing system remains effective even if the pump is severely cavitating or if there is entrained air in the fluid. An auxiliary bearing is standard on all models, to protect the impeller. Pump volatile liquids using a non-metallic mag-drive pump. TB-mag pumps use pressurized radial bearings for increased flash resistance. Increased pump life and reliability are possible because the pressure-balanced impeller greatly reduces stresses on the impeller Silicon carbide replaceable wear parts, including all wear rings, is a standard feature usually found only on expensive pumps such as API pumps. One bolt size eliminates assembly mistakes

Particulates are excluded from the containment shell/inner magnet gap. The wear ring behind the impeller stops large particles from entering and damaging this area. This prevents environmental leaks and protects your investment. Efficiency is equal to sealled ANSI pumps. Low losses and a non-conductive containment shell contribute to high efficiency pumping. The NPSHr is equivalent to standard ANSI installations because the pump has a fully-open impeller eye. Wear rings work as secondary bearings to protect impeller / inner magnet assembly in the unlikely event of a bearing failure.

Figure 1 - Thrust Balancing Pressure Zones

Figure 2 - Valve opening at higher flows. Figure 3 - Valve closing at lower flows.

The TB-mag series mag-drive pumps create three distinct pressure regions around the impeller. These regions are the suction pressure in the impeller eye, the discharge pressure in the volute and the balance pressure behind the impeller (Figure 1). In operation, the balance pressure is approximately one quarter to one third of the discharge pressure. The discharge pressure is created by the routine pumping action of the impeller while the balance pressure is controlled by the combined action of a fixed orifice and a variable orifice. The fixed orifice is created by a set of clearance rings behind the impeller. These rings limit the leakage flow behind the impeller to a relatively constant rate. The leakage then flows around the magnets, past the bushing to the thrust control valve. This thrust control valve combined with the front of the shaft defines the variable orifice. Because the impeller is free to slide axially the variable orifice changes size. As conditions of service change for the pump the impeller will automatically compensate for the pressure change and remain thrust balanced. If the impeller moves forward (Figure 2), the valve is opened to a greater degree and the balance chamber pressure is reduced. This causes the impeller to react with a net force towards the motor. However, the valve is now closing (Figure 3) and the balance chamber pressure increasing. This moves the impeller towards the suction. The net result is a very stable axial position for the impeller. There are no axial bearings and the radial bearings always operate in a pressurized fluid environment. Compare axial thrust loads in (Figure 4).

Figure 4 - Axial Thrust Loads