Double diaphragm pumps – BX251
PP PVDF ALU AISI 316
BX251 pneumatic pumps achieve flow-rate of up 340 l/min. They are engineered for pumping acids with high apparent viscosity from 1 up to 50.000 cps (at 20°C) even if containing suspended solids. Self-priming dry capacity even with considerable suction head, fine tuning of speed without pressure loss and the possibility of dry operation without damage mean that these pneumatic pumps offer unrivalled versatility. These air-powered diaphragm pumps are usually adopted for transferring aggressive liquids in industrial, chemical and petrochemical markets. In particular, the BX plastic range can handle highly aggressive and concentrated acids. Instead, the BX metal range is best suited for solvent-based fluids and for the many different needs of the paint industry.
BX251 technical features
|Material||PP – PVDF – ALU – AISI 316|
|Max flow-rate||340 l/min|
|Max head||70 m w.c.|
|Maximun dry suction lift (self-priming)||6 meters|
|Intake/Discharge connections||G 1” 1/2 f|
|Intake/Discharge flanged connections||DN 40 (upon request)|
|Air Inlet||G 1/2” f|
|Maximum air supply pressure||7 bar|
|Maximum particle size||6 mm max|
|Weight kg||16 (PP) – 20 (PVDF) – 21 (ALU) – 32 (AISI 316)|
|Noise level (at 5 bar with rubber balls)||dB (A) 82|
|Temperature limits||65°C (Polypropilene) – 95°C (PVDF, ALU, AISI 316)|
|Atex certification||II 3/3G D IIB T 135°C (zone 2) II 2/2GD c IIB T 135°C (zone 1)|
BX251 performance curve
Curves and performance values refer to pumps with submerged suction and a free delivery
outlet with water at 20°C. Furthermore, they may vary according to pump material.
Overall dimensions BX251
|BX251 PP – PVDF||254||484||491||415||326||8||138|
The dimensions in the data-sheet are expressed in millimeters (mm). The technical specifications may be subject to variations without prior notice.
|Sectional drawing BX251|
Instructions for use
Everything you would have liked to know about diaphragm pumps but were never told … Some suggestions for a proper use of double diaphragm pumps:
- The air-driven motor of BX pumps is self-lubricating and will not require any greasing. The pneumatic power-supply of our AODD pumps must be made using filtered, dried, non-lubricated, oil-free air, at a pressure not lower than 2 bars and not higher than 7 bars.
- If the pressure is below 2 bars when the pump is running, the pump may stall. At a pressure higher than the maximum threshold, yielding and leakages of the product under pressure may occur and/or the pump may break. Warning: most snap-on fittings cause pressure drops.
- BX Series pneumatic pumps must never be used to create vacuum.
- In case of high viscosity fluids, do not use under-sized filters or piping, especially on the intake side. Furthermore, you must decrease the pump speed by choking.
- Fluid service temperatures must range from +3°C to a maximum of 65/95°C according to the material of the components. Its use is defined by the type of material used to build the pump, the temperature class and the type of fluid. The maximum temperature allowed for process fluid or powder depends on and/or is declassed by the material of the pump: if exceeded, in respect to the maximum temperature shown on the marking, it cannot be guaranteed.
- The declared capacity of dry negative suction refers to the intake of fluids with a viscosity and specific weight equal to 1. The performance and the duration of the pump’s membrane depend on the fluid’s viscosity and specific weight, as well as the length and diameter of the suction pipe.
- The pump with negative dry suction must be installed as close as possible to the point of collection and, in any case, never farther than 5 m.
- Fluid to be pumped with negative suction must never exceed a viscosity of 5,000 cps at 20°C and a specific weight of 1,4 Kg/l. These elements can cause derating and reduce the duration of the diaphragm.
- If the pump is made from conductive materials and is suitable for flammable products, each pump casing must be equipped with a suitable earthing cable. Attention: danger of explosion and/or fire.
- Provide appropriate support for the piping. Piping must be strong enough to avoid deformation during the suction phase and must never weigh down on the pump in anyway or vice versa.
Use only fittings with cylindrical gas threads in materials compatible with both the fluid and the pump’s construction materials.
Discharge UP and intake DOWN. In some pump bodies the arrows must be pointing up.
Pump made from conductive materials and suitable for flammable products: the pump casing must be equipped with a suitable earthing cable.