Lab Mill
Lab Extruder series have been designed and produced to match with mass production result in Powder Coating production line.
It is used in R&D department to achive new product and improve other formulations.
1.Main Characteristic:
1.Some particle size distrubition as production line's grinding system.
2.Pin disk driven with high speed electromotor directly.
3.High efficiency.
4.Easy to clean.
2.Our Advantage & Service:
-Technical Support Online Service Provided
We can supply all Powder Coating Raw Materials( polyester resin, epoxy resin, barium sulfate, gloss agent and so on) in the formulation.
Powder Coating Lab Mill,Laboratory Sample Grinders,Lab Grinder Milling System,Lab Grinding Mill Yantai Yuanli Corp Ltd , https://www.yuanlicorpcn.com
According to customer's requirement, we provide layout (plant designer), excellent mechanical engineer, excellent electrician, etc.
-On-site Training Service Provided
In customer factory, we provide all kinds of training, including installation, commissioning
-Long-term Maintenance Provided
In the area of maintenance, we offer needs-oriented and standardized maintenance packages, such as the overhaul of components, gearboxes, in order to guarantee the safe and economic operation of plant and machinery.
-Spare Parts Replacement and Repair Service Provided
Providing spare parts for all kinds of powder coating processing equipment in long-term. And can provide tailored made spare parts according to customers' requirements. Ensure advanced craft, good material and high precision.
-Formulation Provided (our advantage):
Some customers are worried their final products if can get best result, we have our own formulator (Engineer for powder coating formulation) who is testing and updating the formulation according to customer requirement all the time. And have very good experience for the formulation to support customer to make different effect powder coatings.
Application of metal seal butterfly valve in cryogenic equipment
**Abstract:**
With the rapid advancement of industrial technology, the valve industry has faced increasingly strict requirements. This is especially true for butterfly valves used in low-temperature environments, where not only general valve performance is required, but also specific considerations such as reliable sealing at low temperatures, smooth operation, and other unique demands associated with cryogenic applications. As industrial technologies continue to evolve, the need for high-performance cryogenic valves has grown significantly.
Butterfly valves are known for their compact design, lightweight construction, minimal fluid resistance, and quick opening/closing capabilities. However, in cryogenic applications—such as natural gas liquefaction systems, air separation units, and pressure swing adsorption equipment—metal-sealed butterfly valves are rarely used, with over 80% of valves being gate or globe valves. The main reason for this is the poor sealing performance of traditional metal-sealed butterfly valves at low temperatures, often due to structural irregularities that lead to leakage, which can severely impact the safety and efficiency of low-temperature equipment.
To address these challenges, structural improvements have been made to metal-sealed butterfly valves. A high eccentricity butterfly valve (with a national patent applied) has been developed, capable of operating effectively under both high and low temperature conditions. This paper briefly introduces its low-temperature performance.
First, the sealing performance of low-temperature valves must meet stringent requirements. There are two primary causes of leakage: internal leakage and external leakage. Internal leakage typically results from deformation of the sealing surfaces caused by low-temperature contraction. For example, during a DN250 butterfly valve test using liquid nitrogen (-196°C), the 1Cr18Ni9Ti butterfly disc showed a deformation of about 0.12mm, leading to internal leakage. To solve this, a new design was introduced, changing from a flat seal to a conical seal. The valve seat features an elliptical sealing surface, while the disc includes a flexible sealing ring that can move radially within the groove. When the valve closes, the elastic ring first contacts the minor axis of the elliptical surface, then gradually moves to the major axis, ensuring full contact and effective sealing through elastic deformation. This design compensates for any low-temperature-induced deformation, preventing leakage and jamming. Upon opening, the seal returns to its original shape, minimizing friction and extending service life.
Second, external leakage can occur at flange connections due to mismatched thermal expansion between the gasket, bolts, and valve body. To prevent this, the connection method was changed from flanged to welded. Additionally, stem packing leakage is a common issue with conventional PTFE (F4) seals, which tend to shrink at low temperatures, causing ice buildup and operational failure. A self-shrinking seal structure was developed, utilizing PTFE's high expansion coefficient to maintain a tight seal at both room and low temperatures.
The valve body and stem bushing design also play critical roles. Proper material selection is essential for reliable low-temperature operation. Austenitic stainless steel like 1Cr18Ni9Ti is preferred due to its stability at low temperatures. The valve’s compact size and uniform shape reduce thermal stress and heat capacity, making it easier to cool and manage. For instance, the DD363H type butterfly valve was specifically designed for cryogenic applications, incorporating features like SF-1 composite bearings on the stem bushings to reduce friction and improve performance in extreme conditions.
In summary, metal-sealed butterfly valves now offer advantages such as low flow resistance, reliable sealing, fast operation, and long service life. With ongoing innovations, they are becoming more suitable for use in cryogenic systems, and their application in low-temperature equipment is expected to grow in the future.