Achieving zero leakage in chemical pumps has always been a key goal for manufacturers of chemical equipment. This demand has significantly driven the increasing adoption of magnetic and canned pumps. However, despite these advancements, complete elimination of leaks remains a challenge. Issues such as the lifespan of the magnetic pump's isolation sleeve and the canned pump's shielding sleeve, material corrosion, and the reliability of static seals continue to require attention. Below are some fundamental aspects of sealing that are worth noting:
For static seals, the most common types are O-rings and gaskets. Among these, O-rings are the most widely used due to their versatility. The viscosity of the fluid being pumped can greatly affect pump performance. As viscosity increases, the pump's head decreases, resulting in lower optimal flow rates and head pressures, while power consumption rises, thereby reducing overall efficiency. Performance data provided in catalogs typically assumes water as the medium and may need adjustment when handling viscous fluids. For applications involving thick slurries, pastes, or highly viscous liquids, a screw pump is often recommended.
When it comes to static sealing materials, fluorine rubber is commonly used in chemical pumps, with PTFE reserved for specific cases. Selecting the appropriate material for mechanical seal rings is crucial. While tungsten carbide is effective, its high cost and potential hardness mismatch make it less ideal for certain media. It’s better to choose based on the specific characteristics of the fluid being handled.
In terms of dynamic sealing, chemical pumps rarely use packing seals; instead, they predominantly rely on mechanical seals. These can be single or double-ended, and either balanced or unbalanced. Balanced seals are preferred for high-pressure applications (typically over 1.0 MPa). Double-ended mechanical seals are designed for extreme conditions such as high temperatures, crystallization-prone environments, viscous media, or those containing particles and volatile substances. In these cases, an isolation liquid is injected into the seal chamber, with its pressure typically exceeding the medium pressure by 0.07 to 0.1 MPa.
Addressing these challenges will help improve the reliability and longevity of chemical pumps, ensuring safer and more efficient operations. Further research and development will undoubtedly lead to even better solutions in the future.
Dispenser Mass Flow Meter
Sealand is a trustworthy manufacturer of CNG Dispenser Mass Flow Meter, LNG Dispenser Mass Flow Meter, LPG Dispenser Mass Flow Meter, ATEX, CE & IECEx approved.
With its high accuracy, wide rangeability and reliable performance, Sealand meter has been applied in many kinds of industries during the last 8 years. Unlike others who only focus on the measurement of liquid at normal pressure & temperature, Sealand has conquered the difficulty in the measurement under severe conditions, such as high pressure, high viscosity, high & low temperature.
Take CNG (compressed natural gas) for example. As the saying goes, the meter can measure anything else if it can measure CNG. It is quite hard to measure gas under high pressure. The sensor must be able to bear high pressure; in this way, the thickness of flow tube must be increased, so the transmitter shall be more sensitive to detect the signal; however, Sealand made it. Sealand's first model is specially designed for CNG dispenser, and now thousands of this model are put into use on the market.
Here are the pictures of Sealand Mass Flow Meter in Dispenser for your reference.
CNG Dispenser Mass Flow Meter, LNG Dispenser Mass Flow Meter, LPG Dispenser Mass Flow Meter
Zhejiang Sealand Technology Co., Ltd. , https://www.sealandflowmeter.com