Hydraulic Relief Valve

hydraulic relief valves . purchased a batch of hydraulic relief valves for crane system in because the original supplier was not able to meet the delivery. He sent an email last week saying with hydraulic relief valves, the stability is 8% higher than that of the original supplier, and there is almost no external leakage. This surprised him. The use experience of hydraulic relief valves has benchmarked with their previous local hydraulic relief valve manufacturers The vast majority of hydraulic valve bodies are made of nodular iron, vermicular iron and gray iron and cast with resin sand as the molding medium. Therefore, there is sticky sand in the casting, which is easy to pollute the oil system and block the valve and filter, which is the key factor affecting the stability of hydraulic relief valves. Most of the common sand cleaning methods of hydraulic relief valves used in the industry are shot blasting and electrochemical sand cleaning, all of which have limitations. 1. Shot blasting can not completely remove the sticking sand from the valve hole with complex structure and small oil passage, which is easy to affect the tightness and product accuracy, and is not conducive to the stability of the hydraulic relief valves. 2. Electrochemical sand cleaning can relatively remove the sticky sand in the narrow oil passage, but it has high energy consumption, high operation intensity of workers, easy to have human errors, can not completely remove the sticky sand, and is not conducive to the stability of the hydraulic relief valves. Improving the quality of hydraulic parts processing process, improving the cleanliness level and ensuring the stability of hydraulic relief valves has always been the hard index of hydraulic relief valves. Auxiliary processing of hydraulic parts mainly includes: sand cleaning of valve body, deburring or residue treatment of parts and cleaning of hydraulic parts. How does do the sand cleaning of hydraulic relief valves technical team has continuously improved the sand cleaning process of hydraulic relief valves after years of technical improvement. For the sand cleaning of small complex castings, has its own unique sand cleaning 5 methods, namely: artificial aging - Pickling - rinsing - rust prevention - ultrasonic cleaning. Artificial aging is used to reduce the binding force between the casting and sand, acid pickling is used to remove the oxide skin at the joint between the sand and the casting to peel the sand from the casting, and then the explosion of compressed air during ultrasonic cleaning is used to peel off the sand, so as to achieve the purpose of sand cleaning. has its own unique advantages of sand cleaning 5 methods: (1) it is less affected by the casting structure; (2) it is

When I opened the mailbox this morning, I saw an from , which should be a re-order for the hydraulic relief valve, because he asked about the durability of hydraulic relief valve spool last week. Opening the , it is indeed the need for purchasing a large number of 420 hydraulic relief valves, and requiring 3 years of quality guarantee. is a purchaser of . 3 years ago, a customer of his company complained that the crane was easy to depressurize during work, resulting in the inability of the crane to bear the force. Especially after the working temperature reaches 55 C, the pressure cannot go up. Field engineers believe that this is a problem of the hydraulic system, such as low pressure regulation of the hydraulic relief valve, wear of the hydraulic system, or oil pollution. No abnormality was found after inspection. Finally, it was determined that the fault occurred on the hydraulic relief valve. After disassembling the hydraulic relief valve, it was found that the cone valve spool was worn, affecting the sealing of the hydraulic system, so the oil pressure could not rise. The customer does not understand why the valve spool of this hydraulic relief valve is worn after less than 2 years of use. The customer requested to replace with a batch of hydraulic relief valves with durability of more than 3 years and use them on these 12 faulty cranes. At that time, contacted more than 10 hydraulic relief valve manufacturers and got reply that the warranty could not be achieved for 3 years. Some hydraulic valve manufacturers replied that they only have 50% confidence. This result embarrassed Bruce. The customer requirements for the hydraulic relief valve could not be implemented, how he should explain to the owner. I received message from on the of can really provide a 3-year warranty hydraulic relief valve I replied directly: just give it a try then you will know. I can't make money with the trial orders of several samples, and you can't lose money. Maybe was stimulated and sent us the test order the next day for 4 hydraulic relief valves. also frankly told that two other hydraulic valve manufacturers would also try the order at the same time. Their plan is that each factory will be tested for 4 samples, with a total of 12 hydraulic relief valves to meet the urgent needs of customer first. About 2 years after the samples were sent, we received from again for another trial order of 8 hydraulic relief valves. I felt strange and thought that they actually didn't have big quantity order for hydraulic valves. Until last week, from his email, we learnt that they had tested the hydraulic relief valves provided by for 3 years. Indeed, 3 years later, hydraulic relief valves still worked normally, and the hydraulic relief valves provided by the other two manufacturers had faults in less than 2 years.

For 240L flow rate and 450bar pressure resistance, the service life of hydraulic relief valve is more than twice that of the original manufacturer hydraulic equipment company. At the beginning of last year, the hydraulic station they sold to was complained by the customer in less than half a year. The oil temperature in the hydraulic station was abnormal, as high as 80 , and the efficiency of the whole hydraulic transmission was poor. The after sales service found that the hydraulic relief valve was stuck, which affected the load relief and caused the oil to heat up. The original hydraulic relief valve manufacturer believed that the jamming was caused by unclean hydraulic oil. After detecting the hydraulic oil, there was no abnormality. When disassembling the hydraulic relief valve, it was found that the contact surface between the valve spool and the valve hole was worn, which should be caused by the coaxiality deviation between the valve spool and the valve hole of hydraulic relief valve, resulting in the jamming. The original manufacturer agreed to replace it, but half a year later, the old problem happened again, and was criticized. had to find manufacturers with long service life of hydraulic relief valves. He contacted many manufacturers and found that most of them were not able guarantee a service life of over 1 year for the hydraulic relief valves with a maximum flow of 240L and a pressure of 450bar, but only 6 months. Finally, only 3 manufacturers were willing to test samples, including . engineers determined that the material selection was a key step according to the parameter requirements of the hydraulic relief valve. After 2 months, 30 samples of hydraulic relief valve were sent out. Last week, we received the PO of hydraulic relief valves from . He said that although was the latest to deliver the samples, in the service life test, the hydraulic relief valve samples provided by the 3 manufacturers showed that only had no abnormalities after a service life of more than 1 year. For this kind of customized, high demand and non-standard hydraulic relief valve, our 3 advantages are not available in most manufacturers . 1. The durability of hydraulic relief valve mainly depends on the material selection according to the working conditions. For this hydraulic relief valve, selects 20CrNi2MoV high carburized bearing steel pretreatment process, through secondary quenching cryogenic treatment low temperature tempering process, it is cooled to 650 ~ 700 and then discharged after being cooled to 450 ~ 500 The microhardness is 237 247 HV, and its wear resistance and contact fatigue performance are increased by more than 3 times. The heat treatment of this material is difficult to control, and most manufacturers cannot control it.

used imported tools to solve the problem of rough inner hole of hydraulic relief valve. David came back after being cheated elsewhere Half a year ago, , an customer, sent an inquiry to about 500 pilot operated hydraulic relief valves. This hydraulic relief valve is difficult to process the inner hole. Our cost accounting department gave a reasonable price. 3 days later, informed that the price of the hydraulic relief valve was 16% higher than that of other manufacturers and he could only place the order with other hydraulic relief valve manufacturer. As far as I know, there are not many manufacturers who can make this hydraulic relief valve. The price provided by this time should be very cost-effective. As is our old customer, we never quote prices indiscriminately. I always believe that it is also a sign of dishonesty to quote prices indiscriminately. Last month, asked again whether the hydraulic relief valve quoted last year could maintain its original price. I asked him curiously, hasn't this hydraulic relief valve placed an order yet truthfully told us that last time, the pilot operated hydraulic relief valves purchased in another manufacturer were reported by the users that the stability was poor and the valve was often stuck. They decided to get replacements. contacted the original manufacturer of the hydraulic relief valves, but the manufacturer was unwilling to offer replacements. Because there were too many complaints, David did not dare to ask the original manufacturer to re produce, so he emailed . was very cautious this time. He specially sent us 5 samples of hydraulic relief valves from the original manufacturer. After receiving and checking, we found that the inner hole of the hydraulic relief valve has a taper, the processing size is not accurate, and the surface roughness Ra is as high as 1.6m. The root cause of these problems is that the processing tool rotates improperly, which also shows that the original manufacturer is not good at processing this special inner hole. No wonder there are so many complaints. It is wise for to change the factory. was satisfied with our diagnosis of this hydraulic relief valve and asked us to make samples as soon as possible. 1 week later, sent the samples of hydraulic relief valve, and approved our samples at one time. They specially compared hydraulic relief valves with that of the original manufacturer. Their engineers admired the inner hole processing of , which not only has no taper, but also has more than twice the accuracy of the original manufacturer. For the special inner hole of this pilot hydraulic relief valve, adopts CBN cubic boron nitride cutter from to replace the conventional ceramic cutter. Most hydraulic relief valve manufacturers dare not use this cutter, which is not only costly,

AAK unique 5 steps sand cleaning method replaces the traditional method commonly used by peers, and completely solves the problem of valve stuck or filter blockage of hydraulic relief valves caused by hidden danger in sand cleaning. The American customer placed an order for the hydraulic relief valves to AAK 3 days after the test run. Most of the bodies of the hydraulic relief valves are made of nodular iron, vermicular iron and gray iron and cast by sand turning with resin sand as the modeling medium. Therefore, there is sticky sand in the casting, which is easy to cause valve jamming and filter blockage. Most of the common sand cleaning methods of hydraulic relief valves in the same industry are shot blasting and electrochemical sand cleaning. These methods have limitations and are not conducive to the stability of hydraulic relief valves. Gabriel is a purchaser of a hydraulic company in the United States. In previous years, he purchased the hydraulic relief valves in the United States. Recently, there is an order for hydraulic relief valves. The production of the original domestic manufacturer is full schedule, while the other hydraulic relief valve manufacturers dislike the small quantity and are unwilling to accept the order. The company asked him to check with Chinese hydraulic relief valve manufacturers. Among several hydraulic relief valve manufacturers recommended by his colleagues, Gabriel chose 3 of them to send samples after a round of comparison. After 20 days, the samples of these 3 hydraulic relief valve manufacturers were generally stable and prone to valve jamming or filter blockage. The root cause was the incomplete sand cleaning process of the hydraulic relief valves. When browsing B2B websites, Gabriel saw that AAK website www.aakindustry.com introduced the 5 steps sand cleaning method of hydraulic relief valves. He left a message on our website: Can AAK make the hydraulic relief valves not stuck or the filter not blocked? We replied him directly: AAK hydraulic relief valves with 5 steps sand cleaning method have been recognized by German customers. You are welcome to try the order. Gabriel subconsciously approved AAK hydraulic relief valves but was still some concerned because of no cooperation before, so he asked for samples to test first. According to the draft of hydraulic relief valves sent by him, we sent samples in 2 weeks. Gabriel issued official PO on the 3rd day after receiving the hydraulic relief valve samples for commissioning, and requested that the bulk goods to be 100% sand cleaned thoroughly. AAK adopts more efficient sand cleaning method and has its own unique 5 steps sand cleaning method for small and complex castings, namely: Artificial aging - Pickling - Rinsing - Rust prevention - Ultrasonic cleaning. Artificial aging is used to reduce the binding force between the casting and sand, acid pickling is used to remove the oxide skin at the joint between the sand and the casting,

AAK hydraulic relief valves won the PK from more than 30 hydraulic valve manufacturers by using 3 points for quality positioning Madison is from WHITE company in the United States. 1 year ago, he found AAK Hydraulic Valves through Google. He wanted to develop a hydraulic pilot operated relief valve. After 2 rounds of PK, AAK hydraulic valves stood out from more than 30 hydraulic valve manufacturers and received the trial order for 30pcs of hydraulic pilot operated relief valves. The trial order requires that all parameters must be benchmarked with HydraForce. I replied that AAK Hydraulic Valves is the supplier of HydraForce for 9 consecutive years. The quality of HydraForce is the most basic commitment of AAK. 1 month later, 30 samples of hydraulic pilot operated relief valves were sent out, and Madison had no response. I did't have any follow-up. As long as these samples are approved by the customer, the customer will actively feedback the test results and will come to re-purchase this hydraulic pilot operated relief valve. 1 year later, that is, yesterday, I received Madison's e-mail. I knew that it must be the re-order before I did not read the email. Madison said that after 1 year's use, AAK hydraulic pilot operated relief valve has reached the standard, and 800 more hydraulic pilot operated relief valves are needed. Madison also specifically mentioned that AAK hydraulic pilot operated relief valve is completely comparable to HydraForce in quality and function, and the internal leakage control is 20% higher than that of HydraForce, and the performance is more than 2 million times. In the past year, AAK Hydraulic Valve was the most satisfied hydraulic relief valve manufacturer of their entire technical team. Not only did the manufacturing quality match the standard of HydraHorce, but also the price was about 30% cheaper. I know that there are many hydraulic valve manufacturers in Ningbo, but there are not many hydraulic valve manufacturers such as AAK that insist on "high quality, excellent function and strong performance", perhaps not more than 3. In my early years, I understood the importance of choice from the Scrolls. One's greatest strength is the power of choice. Since its inception, AAK has made a quality positioning for hydraulic valves, which makes AAK become one of the suppliers of six top 500 enterprises in the world. AAK's strength mainly depends on 3 important points: human, machine and material: 1. AAK engineers have more than 20 years of industry experience, not only have strong design and R & D capabilities, but also know the details of each processing of products. 2. In terms of finishing equipment, AAK has the NP520X-F full-automatic universal grinder of Japan Long Island, which can achieve surface of the processed valve spool is like a mirror, and the precision control is excellent.

AAK reduced the shape of the hydraulic relief valve by 35%, allowing the motor installed into the manifold, which can not be achieved by peers Jimmy is from a hydraulic equipment company in the United States. He has cooperated with AAK for more than 2 years and is very sticky about the quality of hydraulic relief valves. At the end of last year, the hydraulic pilot operated relief valve used in the hydraulic unit they developed could only be purchased from local manufacturer because of tight time. Problems were encountered in the hydraulic manifold installation. The existing hydraulic relief valve of the American factory occupied a little position of the motor, resulting in difficulties in the installation of the motor. If the position of the hydraulic relief valve is changed, the manifold oil circuit will be changed and the power supply of the hydraulic system will be affected. The manufacturer of the hydraulic pressure relief valve has no time to adjust the size. Jimmy had to look for other manufacturers of hydraulic pilot operated relief valves. After a week, he found more than 10 local manufacturers of hydraulic relief valves in the United States. Some of them were not willing to customize it due to small quantity, while some gave no reply at all. Jimmy was very helpless. Jimmy thought of AAK Hydraulic Valves in Ningbo and asked how long it would take to produce 10 non-standard hydraulic pilot operated relief valves? I felt his anxiety and asked if he had encountered any difficulties in purchasing hydraulic relief valves. Only then did he tell me the embarrassment he had encountered in domestic manufacturers in the United States. According to the drawings and manifold schematic diagram of the hydraulic pilot operated relief valve provided by him, AAK engineers also suggested that the hydraulic pilot operated relief valve should be redesigned to reduce the length of the hydraulic pressure relief valve by 35%. AAK can send 10 hydraulic pilot operated relief valves within 30 days. Their engineers doubted this innovation, because if the size is reduced by 35%, the load of the hydraulic pilot operated relief valve will be affected. We understood the concerns of their engineers. We would see the result in a month. If AAK hydraulic relief valve can not solve the problem of the manifold installation, we were willing to bear the loss. Jimmy was waiting for the sample of AAK with worry. After the samples were sent out, we soon received email from Jimmy. AAK newly designed hydraulic relief valve was successfully installed into the manifold, and the equipment commissioning was normal. Their engineers were satisfied. They were curious to know how AAK hydraulic pilot operated relief valve was reduced by 35% under the condition of ensuring parameter.

The old customer in the Netherlands who did not change the factory easily failed again and again. AAK hydraulic relief valves settled it at one time Marten is an old customer from a Dutch hydraulic company. He is very cautious in the business of hydraulic valves and never changes hydraulic valve suppliers easily. AAK hydraulic valve reached the first cooperation of hydraulic relief valves under the introduction of his friend. It has been 3 years, and he orders 2 types of hydraulic relief valves with AAK every year. We have a very good personal relationship, and often communicate about some hydraulic valve technology. Last month, Marten had an order for a special hydraulic relief valve that requires a surface roughness Ra of 0.1~0.2�¼m, which is more than 4 times accurate than the normal standard. All the hydraulic relief valves of this series are purchased from the hydraulic valve manufacturer that he has cooperated with for 5 years. This manufacturer has tried this hydraulic relief valve for 3 consecutive times, but the Ra value is still not up to standard. Marten thinks of AAK hydraulic valve. In the email, he has been emphasized that the surface roughness Ra value of hydraulic relief valve must reach 0.1~0.2�¼m. According to the hydraulic relief valve drawings sent by Marten, after discussion, AAK engineers expressed 90% certainty that the Ra value could reach 0.1~0.2�¼m. Marten seems to see hope, but also fear. He asked AAK TO try samples immediately. At the same time, the original hydraulic relief valve manufacturer was also requested to continue the sampling. AAK arranged the most experienced technicians to operate the knife, first of all in the rough turning stage, cutting depth adjustment to 0.8~1.5mm, feed to 0.2~0.3mm/r, cutting speed to 30~50m/min and so on, after the rough turning Ra value is 12.5~6.3�¼m, while leaving 0.5~1mm as fine turning margin; Secondly, in the finishing stage, the cutting depth is adjusted to 0.1-0.3mm and the small feed is 0.05-0.2mm /r. At the same time, the cutting speed is ensured to reach the moderate value and the roughness Ra value is ensured to reach 0.2-0.16�¼m. AAK sent the hydraulic relief valve samples 10 days later. On the 3rd day after receiving the samples of AAK hydraulic relief valve, Marten informed us by email that the Ra value of the surface roughness was up to standard. At the same time, he also informed that the original hydraulic relief valve manufacturer also continued the sampling, but failed in 5 samples for 5 times, while AAK succeeded in one time. He asked us to catch time to prepare material, he would discuss the PO of hydraulic relief valve with AAK after he confirmed the order quantity and the delivery date with his customer. For high precision hydraulic relief valve roughness Ra value, in addition to use high precision lathes, good technicians are the key, to be good at adjusting lathe parameters according to different

According to the financial dept this morning, there was a sample fee for hydraulic pilot-operated relief valves. I knew it was from ROQUET company in Spain. One year ago, Domingo in their company had a hydraulic pilot-operated relief valve that needed AAK to make samples, but was unwilling to pay $2,000 of the sampling fee. The original factory didn't need them to pay, so they chose that factory to produce this hydraulic pilot-operated relief valve. Last week, Domingo came to me again to ask if there was time for sampling and they would pay the sampling fee. After communication, it was learned that the hydraulic pilot-operated relief valves shipped by the original factory were used in the hydraulic power unit. Less than half a year, it was reported for repair by the customer. It is easy to have insufficient power supply of the hydraulic system during the construction process. The after-sales engineer found that the wear of the valve spool of the hydraulic pilot-operated relief valves led to leakage. He had to use the alternative pilot-operated relief valves first and asked Domingo to contact the original manufacturer to solve the problem. The original manufacturer reported that the hydraulic pilot-operated relief valves had not been worn for more than 1 year previously. The working pressure is more than 450bar this time. The domestic hydraulic pilot-operated relief valves can only have a service life of half a year. If you want to find a hydraulic pilot-operated relief valve with a service life of more than 1 year, you can only buy it from HAWE in Germany. They are the best manufacturer of hydraulic pilot-operated relief valves with high pressure resistance in the world, but the price is estimated to be more than twice that of Chinese manufacturers. Domingo was a little helpless and asked the boss whether to purchase directly from HAWE in Germany or continue to look for hydraulic pilot-operated relief valve manufacturers in China. Because the alternative hydraulic pilot-operated relief valves were used on the construction site, they still had a 6-month buffer period. The boss asked him to look for the hydraulic pilot-operated relief valves under high pressure at the same time. At this moment, he thought of AAK. When I told him that the key point of the service life of this hydraulic pilot-operated relief valve is to resist high pressure, AAK has an engineer who has worked in HAWE Shanghai factory for 8 years, our production of high-pressure hydraulic valves is just to benchmark with that of German HAWE company, he seems to realize that perhaps AAK can sample a hydraulic pilot-operated relief valve with a service life of more than 1 year this time. AAK replied that it could complete the samples of 12 hydraulic pilot-operated relief valves within 1 month, and the warranty was more than 1 year. Domingo remitted the sample fee of US$2,000 the next day.