Q. Are there any special requirements for OEM purchases?
A. Yes. Liangchuan requires proof of trademark registration in
order to print or emboss your trademark onto the product or
packaging.
Q. Do Liangchuan products come with a warranty ?
A. Yes. That's why we offer 3-year product life guarantee, and a
generous1 year warranty on all purchases that begins with the bill
of loading.
Q. How can I get some samples?
A. Usually we don’t offer free sample and express fee are required,
the sample cost can be deducted from your first large order.
Q. What's the MOQ of your products?
A. Our MOQ is one (1) piece/set.
Q. Are you a manufacturer with your own factory?
A. Yes, we are the manufacturer for more than 8 years
Advantage Of our company
1. Excellent technology:
the technology is in the leading level in China, cooperate with the
most famous
universities in China;
2. Advanced equipment:
advanced processing equipment and testing means, providing the
integration of automation system solutions for product,
engineering, service and training.
3. Strong team:
have many senior engineers with plenty of research, development,
design
experience, providing professional service for sales and after
sales.
4. Good quality:
reliable and stable quality, good performance, long life time.
5. Full series of products:
covers full category of valves, meet the general standard of every
country in the world, such as GB, DIN, ASTM, BS, JIS.
6. Professional after sales service:
have the professional engineer team to provide the service.
7. Certificates:
passed the ISO9001 certificate as well as CE,ISOetc.
8. Fast delivery time:
have the stock, fast delivery time could be guarantee.
9. Packing:
packing strictly as per the exporting standard or as per the
customized request.
10. Long-term quality warranty time:
provide 12 months quality warranty time.
After-sales Service
For your company to order valve products in our company, our
factory makes the following commitments in terms of after-sales
service:
1. Our company implements warranty on product quality;
2. After the contract is signed, guarantee the quality and
quantity, and deliver on time;
3. The company ensures that the valve products provided meet the
contract targets
4. For technical consultation of the demand side, give answers at
any time;
5. When delivering the equipment, the factory delivers the
following materials to the purchaser: delivery list, product
certificate, product sample, product instruction manual, technical
information;
After receiving a letter or a phone call from the user regarding
quality issues, we guarantee a response within 24 hours to resolve
the issue as quickly as possible
Commom Valve Assembly Methods
Common valve assembly methods
The whole machine is the most basic unit of valve parts, and parts
of the valve composed of several parts (such as valve cover, valve
clack parts, etc.). The assembly progress is called general
assembly. Assembly work has a great influence on product quality,
even the design is accurate and the parts are qualified. If the
assembly is improper, the valve will not meet the specified
requirements, and even seal leakage will occur. Therefore, it is
necessary to pay special attention to the use of fair assembly
methods to ensure the quality of the final product of the valve. In
the production, the assembly process defined in the form of a
document is introduced into the assembly process specification.
There are three commonly used assembly methods for valves, namely,
complete replacement method, repair method and selection method.
1 Complete swap method
When the valve is assembled using the complete interchange method,
each part of the valve can be assembled without any trimming and
selection, and the assembled product can meet the specified
technical requirements. At this time, the valve parts must be
processed completely in accordance with the design requirements to
satisfy the requirements of dimensional accuracy and geometric
tolerances. The advantages of the complete interchange method are:
assembly work is simple and economical, workers do not need a high
degree of skill, the production efficiency of the assembly process
is high, and it is easy to organize assembly lines and organize
specialized production. However, in absolute terms, when adopting a
complete replacement assembly, the machining accuracy of the parts
is higher. It is suitable for valves with absolutely simple
structures such as globe valves, check valves, ball valves, and
valves with medium and small diameters.
2 Selection method
The valve is assembled by matching method, and the whole machine
can be processed according to economic precision. When assembling,
a certain size with adjustment and compensation function is
selected to achieve the specified assembly accuracy. The principle
of the matching method is the same as that of the repair method,
except that the method of changing the size of the compensation
ring is different. The former is to change the size of the
compensation ring by selecting accessories, and the latter is to
change the size of the compensation ring by trimming the
accessories. For example: the top core and adjustment gasket of the
control valve type double-disc wedge gate valve, the adjustment
gasket between the two bodies of the split ball valve, etc., is to
choose special parts as compensation parts in the dimensional chain
related to assembly accuracy. Adjust the thickness of the gasket to
achieve the required assembly accuracy. In order to ensure that the
fixed compensation parts can be selected in different situations,
it is necessary to pre-manufacture a set of gaskets and shaft
sleeve compensation parts hydraulic control valve models of
different thickness sizes for selection during assembly.
3 Repair method
The valve is assembled by the repairing method, the parts can be
processed according to economic precision, and then a certain size
with adjustment and compensation function is repaired during
assembly to achieve the specified assembly goal. For example, the
gate plate and valve body of the wedge gate valve, because the
processing cost required to realize the interchange is too high,
most manufacturers use the repair method. That is, in the final
grinding of the gate sealing surface to control the opening size,
the plate should be matched with the opening size of the valve body
sealing surface to achieve the ultimate sealing requirement.
Although this method adds the plate matching process, it greatly
simplifies the dimensional accuracy requirements of the previous
processing process. The special personnel of the plate matching
process are skillful, and generally speaking, it will not affect
the production efficiency. Valve assembly process: The valves are
individually assembled on a fixed site. The valve parts and
components assembly and general assembly are carried out in the
assembly workshop, and all the required parts and components are
transported to the assembly site. Usually component assembly and
general assembly are distinguished by how many groups of workers
are carried out at the same time, which not only shortens the
assembly cycle, but also facilitates the application of special
assembly tools, and the requirements for the skill level of workers
are relatively low.
Some foreign manufacturers or high-tech valves also adopt the mode
of assembling the suspension line or assembling the rotary table.
