CR Pump Mechanical Seal JMK with ≤0.6MPa Pressure and -20~+150℃ Temperature

CR Pump Mechanical Seal JMK

The JMK series is a precision-engineered mechanical seal designed specifically for Grundfos CR pumps. It features a balanced design with components manufactured from corrosion-resistant materials, typically incorporating a silicon carbide rotating face and a stationary seat to ensure reliable, leak-free operation in demanding applications. This seal is engineered for optimal performance in handling various fluids, maintaining the high efficiency and longevity expected of CR pump systems. Standard configurations are available for shaft sizes such as 12 mm.

• Performance Parameters: It can operate at a speed of up to 20 m/s, within a temperature range from -30°C to +180°C, and withstand a maximum pressure of 40 bar, enabling it to adapt to a variety of working conditions.
• Structural Design: It features a cartridge structure, which simplifies installation and maintenance. There is no need to measure the sealing working length. During installation, simply sleeve it on and tighten the bolts of the sealing cover to ensure the assembly quality and avoid leakage issues during startup.
• Sealing Materials: The sealing face materials are typically silicon carbide, tungsten carbide, etc., possessing high hardness, wear resistance, and corrosion resistance. The secondary seal often uses fluorine rubber, ethylene propylene diene monomer (EPDM) rubber, etc., which can adapt to different working media and temperature conditions.
• Quality Assurance: The production process strictly adheres to quality control standards. From raw material procurement to finished product inspection, each stage is closely monitored to ensure reliable product quality, stable performance, and a long service life. It usually comes with a warranty period of up to 12 months.

Products Description:

Pump Mechanical Seal suitable for Grundfos Pump

Product Description

--- Sealing Ring Main Performance Index

Q1: What is the primary application of the JMK mechanical seal?
A1: The JMK seal is engineered specifically for Grundfos CR series multi-stage centrifugal pumps. It is designed to handle clean, thin, non-aggressive fluids like water, making it suitable for applications in domestic water systems, pressure boosting, and industrial circulation.

Q2: What are the typical face materials used in the JMK seal, and why?
A2: The standard configuration typically features a rotating face of Silicon Carbide (SiC) and a stationary seat of reaction-bonded Silicon Carbide. This material combination offers superior hardness, excellent thermal conductivity, and outstanding corrosion resistance, ensuring long-term reliability and minimal wear in clear water applications.

Q3: Is the JMK seal a cartridge or component seal?
A3: The JMK is a component-type mechanical seal. It requires precise installation and setting of the individual components (e.g., rotating face, spring, stationary seat) directly onto the pump shaft and into the seal housing, as opposed to a pre-assembled cartridge unit.

Q4: What is the key differentiating factor of the JMK design for CR pumps?
A4: A key feature is its balanced design. This design mitigates the effects of higher pump chamber pressures, preventing premature face opening and excessive wear. This is critical for maintaining seal integrity across the various stages and operating pressures of a CR pump.

Q5: How do I determine the correct JMK seal variant for my pump?
A5: The correct variant is determined by the specific CR pump model (e.g., CR 5, CR 32) and the pump's shaft diameter. Always cross-reference the JMK part number (e.g., JMK-12 for a 12mm shaft) with the OEM's parts list for your pump's serial number to ensure compatibility.

Q6: What are common symptoms of a failing JMK mechanical seal?
A6: Primary indicators include:

• Persistent visible leakage from the seal gland area.

• Crystallization or mineral deposit buildup around the seal faces.

• Unusual noises from the pump seal chamber, potentially indicating face damage.

Q7: Can I use the JMK seal with fluids other than water?
A7: The standard JMK seal with SiC/Carbon faces is for clean, non-aggressive fluids. For alternative media like mildly aggressive fluids or glycol mixtures, consult the manufacturer's chemical resistance charts, as alternative elastomers (like EPDM instead of Nitrile) or face materials may be required.

Q8: What is the importance of the elastomer bellows in the JMK seal?
A8: The elastomer bellows (typically Nitrile) serves multiple functions: it acts as a static seal on the shaft, accommodates minor axial and angular misalignment, and provides a spring-loaded force to maintain contact between the primary seal faces during operation and thermal expansion.