DINKONDA GLOBAL Power Plants Special DF Type Corrosion-resistant Stainless Steel, Duplex Steel Horizontal Single Suction Multi-stage Centrifugal Pump

DINKONDA GLOBAL Power Plants Special DF Type Corrosion-resistant Stainless Steel, Duplex Steel Horizontal Single Suction Multi-stage Centrifugal Pump

Product Overview
The DF type corrosion-resistant multi-stage centrifugal pump is a single suction, multi-stage, and segmental centrifugal pump. It is an improved design by our company based on the D-type clear water multi-stage pump, suitable for transporting corrosive media. The pump adopts the hydraulic model recommended by the country and has the characteristics of high efficiency, wide performance range, safe and stable operation, low noise, long service life, and easy installation and maintenance. The DF type corrosion-resistant multi-stage centrifugal pump is directly driven by the prime mover through an elastic coupling, allowing for an inlet pressure of 0.6 MPa. It is mainly suitable for various purposes such as urban high-rise building water supply and drainage and fire water, factory and mine water supply and drainage, long-distance water transmission, production process circulating water, HVAC air conditioning circulation, domestic water, etc. It is also a commonly used acid and corrosion-resistant pump in the chemical industry. If the user has special requirements for the material and structure of the pump, our company can change the material of the overcurrent components and pump casing, the inlet and outlet directions of the pump, etc. according to the user's needs, and can achieve the multi outlet structure and function of the DF type corrosion-resistant multi-stage centrifugal pump.

Scope Of Application

The DF type corrosion-resistant multi-stage centrifugal pump is made of materials such as 304, 316, 316L, duplex steel, etc. It is suitable for conveying clean water or physically and chemically stable media with solid insoluble matter volume not exceeding 0.1% per unit volume and particle size ≤ 2mm at temperatures ranging from -20 ℃ to 105 ℃, similar to clean water. It can also be used for conveying corrosive liquids with pH values ranging from 5 to 10.

Welding Process

Although stainless steel pump components have good corrosion resistance, their surface hardness is generally not high. Under conditions containing solid particles or high-speed relative motion, parts such as the mouth ring, liner, and balance plate wear out quickly. Our company prioritizes the hard alloy overlay welding solution for surface treatment of stainless steel parts. This process forms a dense wear-resistant layer on base materials such as 304, 316L, 2507 duplex steel, F55, etc. by argon arc welding with Stellite alloy or tungsten carbide based alloy.
The thickness of the weld overlay varies from 0.3mm to 4.0mm according to the working conditions of the parts, and the post weld hardness is HRC46-60 (the tungsten carbide layer can reach HV1250 or above). Compared with surface treatments such as nitriding and high-frequency quenching, the thickness of the weld overlay is larger and the hardness gradient is smoother, which can maintain dimensional stability for a long time even under combined corrosion and wear conditions. For high head multi-stage pumps, the reliability of the mouth ring and balance components directly determines the overhaul cycle of the pump unit. Our company uniformly carries out welding reinforcement on these friction pairs, and controls the hardness difference of the mating surface during assembly to avoid meshing with the mating parts.

Covered parts: impeller mouth ring, shell mouth ring, balance disc, balance sleeve, throttling liner, intermediate liner, shaft sleeve, protective shaft sleeve, thrust disc, etc.

Structural Form And Characteristics
The DF type corrosion-resistant stainless steel horizontal multi-stage pump is installed horizontally, and the rotor part is mainly composed of a shaft and impeller, shaft sleeve, balance plate and other parts installed on the shaft. The number of impellers depends on the number of stages of the pump. The components on the shaft are fastened with flat keys and shaft nuts to integrate with the shaft. The entire rotor is supported by rolling bearings or sliding bearings at both ends, and the bearings do not bear axial force. The axial force is balanced by a balance plate, and a flat plate indicator is installed at the pump end to monitor the wear of the balance plate. The suction port of the pump can be horizontally or vertically upward, and the pump housing parts such as the inlet section, middle section, and outlet section are connected together by tightening bolts. Both ends are equipped with bearing components, and the pump stage is selected according to the user's required head; Shaft seals generally use packing seals, and mechanical seals can also be used according to user needs. The pump rotates clockwise when viewed from the prime mover end, and the motor is configured as a Y3 series motor.

Product Advantages
1. Efficient and energy-saving: Adhering to specialized production, we have unique methods for model selection, mold making, and casting process of water conservancy components in DF type corrosion-resistant multi-stage centrifugal pumps. All overcurrent components are precision cast to ensure the size and smoothness of the flow channel, which is more than 2% higher than the average measured efficiency of ordinary multi-stage pumps on the market, and has a good energy-saving effect.

2. Advanced process equipment: Our company has imported advanced spare parts cleaning equipment from abroad to ensure the assembly performance of DF type corrosion-resistant multi-stage centrifugal pumps. Each part undergoes certified cleaning before final assembly. In addition to normal material testing, hydrostatic pressure testing, and static balance testing, all pump rotor components above level 6 are inspected for shaft runout after minor installation, and the runout value is controlled within 5 threads, followed by dynamic balance testing according to G2.5 level. After final assembly, check the runout and axial displacement of the shaft and coupling again to ensure the assembly quality of the product.

3. Unique structure: Install an O-ring seal on the mating surface between the balance ring and the pump to prevent high-pressure water from entering the balance chamber and affecting the balance effect of the balance disc, reduce wear of the balance disc, and extend the service life of the DF type corrosion-resistant multi-stage centrifugal chemical pump.

4. Reasonable material selection: According to the needs of different users, the material of the balance disk and balance ring can be welded hard alloy, alloy steel or QT600Mn2 alloy ductile iron, with high surface hardness and good wear resistance, which improves the service life of DF type corrosion-resistant multi-stage centrifugal chemical pumps.

5. Good surface quality: The DF type corrosion-resistant multi-stage centrifugal chemical pump adopts precision casting technology and automatic spraying machine to spray paint, with good surface quality, beautiful appearance, durability, and effectively reduces user maintenance costs.