Flexible rubber expansion bellows common problems and solutions

Flexible rubber expansion 

1. Is the flange galvanized?

Yes, carbon steel flange not painting anticorrosive paint must be galvanized in order to avoid rusting. Usually, we choose electronic galvanized and hot dip galvanized, and most of our customers will choose hot galvanizing.

2. What kind of standard of your drilled flange?

Besides Chinese national standard, we also support American standard, German standard, British standard, Japanese standard, European standard and Australia standard. If you can give us the center distance of the hole, the number and diameter, we can also produce customized flange.

3. Does your company have spool type flex rubber expansion bellows?

Yes, considering that the pipe length will be longer or shorter than the expectation after finishing the installation of the pipes and the cost of producing new mold is expensive, we can produce spool type flex rubber expansion bellows according to your requirements.

4. Can the inner layer rubber and outside layer rubber be made from different rubber material?

Yes, we can produce the flex rubber expansion bellows according to the environment, and we will choose different rubber for the inner layer and outside layer.

5. Can I only buy ball without the flange?

Yes, and the price will be cheaper. For small diameter flex rubber expansion bellows, we have goods in stock and we can offer you a free hydrotest, but for large diameter flex rubber expansion bellows you need to order.

6. How long is your product’s warranty?

12 month. From the day the customer receiving the goods, we grant a free replacement if the products have any problems during the guarantee period.

7. Can you offer the flex rubber expansion bellows sample?

For standard type we can offer the sample, but the customer will afford the freight. For non-standard or more quantity, we will charge for the sample.

8. Does the flex rubber expansion bellows have inspection report?

Yes, all of our product will be conducted hydrotest and leave the factory with a qualified inspection report.

9. Can you offer the drawing?

Yes, we have a excellent engineer team, and they will offer your professional drawing and technical support.

How to Properly Install and Maintain Metal Expansion Joints?

This article is a brief installation and maintenance guide for metal expansion joints. To better install and maintain the pipe expansion joints, users must obey to certain rules. Please check following tips about something you should and shouldn’t do regarding to pipe expansion joints.

Something you are not supposed to do on pipe expansion joint:

Do not remove any moisture-absorbing desiccant bags or protective coatings until ready for installation.

Do not use hanger lugs as lifting lugs without approval of metal expansion joints manufacturer.

Do not allow weld splatter to hit unprotected metal expansion joints. Protect with wet chloride-free insulation.

Do not drop or strike carton.

Do not exceed a pressure test 1-½ times the rated working pressure of the metal expansion joint.

Do not remove shipping bars until finish installation.

Do not use cleaning agents that contain chlorides.

Do not force-rotate one end of an pipe expansion joint for alignment of boltholes. Ordinary bellows are not capable of absorbing torque.

Do not use chains or any lifting device directly on the bellows or bellows cover.

Do not use shipping bars to retain thrust if tested prior to installation.

Do not hydrostatic pressure test or evacuate the system before installation of all guides and anchors. Pipe hangers are not adequate guides.

Do not use steel wool or wire brushes on pipe expansion joints.

Bellows Pipe Expansion Joints

Something you are supposed to do on pipe expansion joint:

Install single Van stone liners, pointing in the direction of flow. Be sure to install a gasket between the mating flange and liner.

Store the metal expansion joints in a clean dry area where it will not be exposed to heavy traffic or damaging environment.

Use only designated lifting lugs.

It is good practice to leave one flange loose until the pipe expansion joint has been fitted into position. Make necessary adjustment of loose flange before welding.

Remove any foreign material that may have become lodged between the convolutions.

Install the metal expansion joint with arrow pointing in the direction of flow.

With telescoping Van stone liners, install the smallest I.D. liner pointing in the direction of flow.

Make the piping systems fit the pipe expansion joint. By stretching, compressing, or offsetting the metal expansion joint to fit the piping, the joint may be over stressed when the system is in service.

Remove all shipping devices after the installation is complete and before any pressure test of the fully installed system.

Inspect for damage during shipment, i.e., dents, broken hardware, water marks on carton, etc.

Which One Should I Choose? Rubber Hose or Metal Flexible Hose?stainless steel hose

Rubber hose and metal flexible hose are two types of fluid line that installed in pipelines to delivery medium. The purpose of this article is to help you determine which one is best for your application, rubber hose or metal flexible hose? Let’s see their strengths and weakness.

stainless steel hose

A stainless steel hose or metal flexible hose is manufactured by welding the steam and butt of stainless steel hose ends together, and welding the fittings onto stainless steel hose. A stainless steel hose has excellent heat resistance and high pressure rating, it shows great adaptability when applying to high pressure and heat pipelines. Welding is the key procedure in the manufacturing of a stainless steel hose, if welding in a wrong way, a leak path can be created and bad for pipeline operation.

A rubber hose is manufactured by rubber material combining with cord fabric line inside the rubber layer. Rubber hose is easier to set in complex working condition since it has good flexibility. Rubber hose is convenient for replacement and its pressure range ratings up tp 10000 psi. Rubber material has good vibration resistance, thus rubber hose is best for pipelines that require resistance to vibration. However, rubber hose is not suitable for high pressure and strong external force pipelines. Comparing to metal flexible hose, rubber hose has shorter service life, it needs to be replaced in regular time.

In modern fuel gas piping system, more rubber hose is replaced by stainless steel hose. Because stainless steel hose is more safe and durable in use. Please enquiry at best@lanphan.com or call 86-371-67447999.

Where to Find A Reliable Spool Rubber Expansion Joint Supplier?

Spool type rubber expansion joint is designed for the non-standard products, it has the same function with molded type rubber expansion joint, they are all used for compensating system pressure spikes and accommodating axial, lateral and angular movements.

spool rubber expansion joint

Spool type is more expensive than molded type, so do you know why rubber expansion joint suppliers still fabricate spool rubber expansion joint for sale? As a rubber expansion joint supplier, we receive inquires from all over the world, and molded type standard rubber expansion joints are not applicable for all working condition, most working environment require non-standard products to fit for using. In this circumstance, rebuild a mould or revise a mould is too expensive, rubber expansion joint suppliers always recommend customers to order a spool one.

What circumstances should you choose spool rubber expansion joint?

First, length different from standard type, whether too short or too long;

Second, small diameter products require rubber expansion joint suppliers to fabricate full face flange, floating flange rubber joint is difficult to be fabricated to spool type;

Third, drill hole is differ from standard, especially oversize center distance, mould can not meet requirements.

What’s the difference between spool and molded type rubber expansion joint?

For molded type rubber expansion joint suppliers, the mould is made according to different country standard, although preliminary mold production cost is high, but the standard rubber expansion joint order amount is very big, in total the price is preferential a lot with the long time. And mold vulcanization of rubber joint can product non-standard length according to the height of the extended mold.

Spool rubber expansion joint supplier manufacture spool type by hand built process, adjusting the rubber joint spacing rod can well adjust rubber joint length, suitable for different environments, and rubber joint products need not manufactured mould so length can be adjusted, but the price cost is higher.

In summary, model selection should on basis of actual working conditions. We Henan Lanphan is a qualified rubber expansion joint supplier in China, our products exported to worldwide countries and areas, if you are looking for rubber expansion joint supplier, do not hesitate to contact us at best@lanphan.com

How to Avoid Color Fading for Single Sphere Rubber Expansion Joints?Rubber Expansion Joints Workshop

Color fading is a common seen problem for single sphere rubber expansion joints, the causes are diversified. It may relevant with dye optical property, inoxidizability, temperature difference, acid and alkali resistance and resin raw material property. Now Henan Lanphan tell you how to avoid color fading for rubber expansion joints.

Rubber Expansion Joints Workshop

Keep out of the sun. During the production process of rubber joints, the requirements for colorant is divided into 4-8 levels, 4 and 5 level is enough for keeping out of sun condition, but if the single sphere rubber expansion joints will used in strong sunlight outdoor, the light fastness should at least 8 level, add ultraviolet light absorber to injection molding, this is a brilliant idea to avoid color fading for rubber joints.

Also, the dye stability determines color fading degree. Dye component contains metallic oxide and salty matter, which has well heat stability and heat resistant property. The rubber expansion joints mainly made from HDPP and HDPE, injection temperature should higher than 280℃, so dye heat resistant property should take into account. Some oxidizing agent may has chemical reaction with dye under high temperature, this lead to color fading.

Henan Lanphan Industry Co., Ltd. is a professional rubber expansion joints manufacturer in mainland China, located in Henan Province, embraces a rich soil in industry products production, we have the exceptionally advantages, no matter in product quality, or in import and export services. Our rubber expansion joints products mainly includes single sphere, double sphere, triple sphere and four sphere rubber joints, clamp type, flange type and threaded type rubber expansion joints are also available. We can custom-made different type rubber expansion joint as your requirement, if you have any question about our products, please feel free to contact us at any time.

Working Principle and Application of Rubber Check Valve

Rubber check valve or duckbill check valve, the check valve’s diameter gradually reduce along flow direction, and gradually forming a duckbill shape sealing parts, so it is also called duckbill check valve. Generally we use flange or clamp to connect rubber check vale with pipeline. The special design of rubber check valve perfectly overcome the disadvantages of flap valve. This article helps you understand the working principle and application of rubber check valve.

Flange Type Rubber Check Valve

What’s the working principle of duckbill check valve?

The rubber check valve is a full rubber structure, with "positive inflows reverse backstop" new drainage valve product features. It is calculated based on stress analysis and stress for different conditions, different design mechanisms, use of different rubber formulations, make according to a special process. When forward, the water floods from the inlet and tiny water pressure, will be able to open the duckbill check valve. The greater of the pressure, the duckbill check valve opens larger, the greater of the water flow. Reverse work, valve port close naturally, sealed backstop, the larger back pressure, the more tightly of the valve port, sealing the better, maximum back pressure which can be made to withstand varying degrees by an elastic material and the rubber compound.

What’s the application of duckbill check valve?

Our company sells two kinds of rubber check valves: clamp type rubber check valve and flange type rubber check valve.

Lanphan duckbill check valve products have been widely applied in waterproofing system, drain-off system, water pump outlet, aerating system. Its full rubber structure won’t cause sedimentation and stuck, greatly reduced maintenance cost.

What should we notice in rubber check valve installation?

Straight-through elevation type duckbill check valve should be installed on horizontal pipeline, vertical elevation type duckbill check valve and bottom valve should be installed on vertical pipeline, and medium flow direction is from bottom to top.

The installation location of swing check valve is not limited, generally installed on horizontal pipeline, also can be installed on vertical pipeline or material pouring pipeline.

Please mind the medium flow direction when installing the duckbill check valve, the flow direction should according with the arrow direction.

Closing rubber check valve will generate water hammer pressure, it may damage the check valve, pipeline or equipment, please pay special attention to large diameter pipeline or high pressure pipeline.

Development History of Metal Bellows

Metal bellows is the device to absorb shock, compensate displacement, seal, and connect pipeline, has been widely used for automatic control and measuring meter, vacuum technique, mechanical industry, electric power, transportation and atomic energy industry. When does people invent the metallic bellows? How does metallic bellows been invented? Let’s follow Henan Lanphan to get to know the development history of metal bellows.

Metallic Bellows

At first, people sew the animal hide into tubular structure to adapt the needs of production and war. After a long long time, till the late 17th century, Dutch people produced the first longitudinal stylolitic canvas hose, widely used in fire control. Later, rubber appeared in international market and rubber hose is popular at that time. While in some corrosive medium and high or low temperature medium can not be delivered by rubber hose, and then people successfully made corrugation on metal pipe, the metallic bellows comes into being.

In the year of 1855, Germany firstly obtained the patent of metal bellows manufacturing, which make use of the principle of manufacturing jewelry. 30 years later, E.Levavasseur from France and H.Witzenmann from Germany created a new type metal bellows and obtained patent in 1885. This new type spiral metal bellows has better sealing performance, and this model structure has been second improved in 1894, which enables a more balanced stress state.

In the year of 1929, people finally made whole structure metal bellows by pinchbecl alloy materials. Form 1950s, double layer, three layer metallic bellows appear, the manufacturing technology changed quickly: welding, electroforming, hydraulic pressure and mechanical flow forming. Meanwhile, the diameters expands a wide range from 2mm to 500mm, or even larger, corrugation number is up to thousands.

Technology improves society to develop in a rapid speed, maybe metallic bellows will step into a higher grade in the near future.

What Causes Metal Bellows Expansion Joint Failure?

Metal bellows expansion joints of our company have been properly designed and produced to apply in various piping systems. However, failures of metal bellows expansion joint have occurred, users and metal bellows expansion joint manufactures both are possible causers. Although metal bellows expansion joint failures can occur for many reasons, Lanphan’s rich experiences has concluded several certain typical causes of failure as below.

Metal Bellows Expansion Joints

1. Incorrect installation method and insufficient protection measure for the metal bellows expansion joint.

2. Something you do during and after installation. For instance:

Joints with internal liners installed in the reverse direction with respect to flow;

Installing a metal pipe expansion joint in a location other than as prescribed by the installation drawings;

Premature removal of shipping devices;

Springing of metal bellows expansion joint to make up for piping misalignment;

Insufficient protection from mechanical damage due to work in the surrounding area; Insufficient protection of bellows during nearby welding operations and failure to remove shipping devices before placing system in operation.

3. Exceed pressure of the system (in-service or hydro test) and bellows vibration (mechanical or flow induced resulting in high cycle fatigue)

4. Metal bellows expansion joints erosion and torsion.

5. Packing of particulate matter in the bellows convolutions which inhibits proper movement of the bellows.

6. Shipping and handling damage. For instance:

Denting or gouging of bellows from being struck by hard objects (tools, chain falls, forklifts, adjacent structures, etc.);

Improper stacking for shipping or storage;

Insufficient protection from weather or other adverse environmental conditions.

7. Improper anchoring, guiding and supporting of the system.

8. Internal and external metal bellows expansion joints corrosion.

9. Excessive bellows deflection, that is axial, lateral, angular deflections greater than design values.

10. Also anchor failure in service.

website:http://www.bestexpansionjoint.com

What Should We Notice in Operating a Rubber Hose?

Lanphan rubber hose also called as flexible rubber hose, according to different transmission medium, select different manufacturing material. Rubber hose is a kind of flexible rubber pipe whose function is to delivery material and medium of all kinds liquid and powdery solid(under positive and negative pressure), such as alcohol, fuel oil, lubricating oil, emulsified liquid, and pumping or discharging gasoline, kerosene, diesel oil, engine oil crude oil and mineral oil under normal temperature. Flexible rubber hose is composed of inner rubber layer, one steel wire braid layer(or multilayer cloth braid or twined) and outer rubber layer. For flexible rubber hose connection type, there are flange connection and clamp connection. Comparing to rigid pipe, the biggest feature of flexible rubber hose is its flexibility.

rubber hose

According to different service conditions and property requirements, flexible rubber hoses are different in thousands of ways, commonly seen specification includes dimension, pressure, length, tortuosity, chemical durability and so on. Flexible rubber hose embraces advantages of long service life, wide dimension range, high loading capacity, excellent impulsion property, wide temperature range, excellent oil resistance, resistance to heat, light and durable in use. The flexible rubber hose is widely used in petroleum, chemical engineering, ships, tanker, agriculture and food industries, its application range covered every production-manufacturing.

Maters needs attention for flexible rubber hose usage:

1.Please use flexible rubber hose within suggested temperature and pressure limit.

2.The flexible rubber hose will expand and shrink with its internal pressure, so the actual length of flexible rubber hose should slightly longer than required length.

3.Please slowly open or close any valves when applying pressure, to avoid shocking pressure.

4.Please use the flexible rubber hose beyond its bending radius, otherwise, it will break off and reduce compression resistance.

5.When apply rubber hose to delivery powder and particle, it is easy to wear, please try to add the bending radius of flexible rubber hose.

6.When near by metal parts, please don’t use the rubber hose in extreme bending condition.

7.Don’t contact or near to fire.

8.Don’t trample the flexible rubber hose by car.

Matters need attention for flexible rubber hose assemble:

1.Please select suitable connector for flexible rubber hose.

2.When insert the connector to rubber hose, please smear oils on rubber hose and connector.

3.Don’t use one time push-in connector, it may cause fracture.

4.Please use professional sleeve or ribbon.

5.Don’t use connector which has scar or rust.

Matter needs attention for flexible rubber hose inspection:

1.Please inspect for the flexible rubber hose before using, make sure there has no damage, harden, soften, color changing and so on.

2.Please regular check the flexible rubber hose once a month.

How to Make an Enquiry on Flanged Expansion Rubber Joint?

The flanged expansion rubber joint is the ideal plumbing setting and pipeline laying out equipment, it becomes the essential pipe connection element in piping system. The flanged expansion rubber joint consists of internal layer, fabric reinforced casing ply and external rubber layer, connect with clamp or flange to compensate movements in pipelines.

rubber pipe expansion joint

Rubber materials of NR, NBR, FKM, EPDM, IIR, CR, EPDM could be used separately or combined to suit for different medium and environment. The rubber pipe expansion joint installed in pipeline to bear pressure, absorb shock, reduce noise and compensate movement.

Knowing the basic facts of a rubber pipe expansion joint, we’d like to offer you the matters should pay attention when making an enquiry on flanged expansion rubber joint. Following are the notices for your information.

Firstly make sure to give detailed technical parameter such as diameter, length, pressure and flowing medium in pipeline to rubber pipe expansion joint suppliers.

Then it comes to rubber material selection. EPDM rubber is applicable for high temperature below 150℃, it is acid and alkali resistance, corrosion resistance, power plant desulfurization, lime slurry, gas, etc; NBR is best for oil medium, including hydraulic oil, aviation oil and other aviation oil, the temperature below 80 degrees; NR is best suited for water, air, compressed air and temperature below 80℃; IIR is wear-resistant, usually used in mining occupations, particulate media delivery pipeline; FKM suitable for high temperature pipeline, it has good resistance to weak acid, strong acid; some applications require Teflon lining inside the rubber pipe expansion joint to resist acid, alkali, emulsion, dilute sulfuric acid, it better to use with temperature range of -40℃ to 150℃, and other special mining environment.

Other notices that need to know: flanged expansion rubber joint should be far away from heat. Bolts should be tightened by symmetry gradually to avoid partial leakage. Fixed support or fixed bracket is necessary when actual axial pressure on rubber pipe expansion joint is bigger than support of pipeline. Actual axial pressure on flanged expansion rubber joint should be less than the support of pipeline to avoid possible pulling off.

The Chinese Spring Festival holiday begin from 10th, Feb. to 22th, Feb., if you have new enquiry awaiting for quotation, please send to us as soon as possible.

Multiple Uses of Rotovap Extraction

We are very familiar with rotary evaporator or rotovap, but do you know the multiple uses of rotovap extraction ? In traditional ideas, we treat rotary evaporator as a rotovap extraction equipment that used in chemical laboratories. In fact, rotary evaporator uses in multiple industries that you can’t even imagine.

rotovap extraction

Rotary evaporator uses: kitchens in luxury hotels

The rotovap extraction is used to evaporate water and extract solvents, what’s the purpose of rotovap extraction in a kitchen? Nowadays, more and more chefs are using rotovap extraction to get high purity foods, for example, using a rotovap extraction method to evaporate the water in fruit juice and get a glass of rich fruit juice, which is more healthier than additive juice. More than a glass of fruit juice, rotary evaporator uses even spread to cake making when getting thick vegetable juice.

Rotary evaporator uses: R&D in cosmetics company

Cosmeceuticals is a popular cosmetics that produced and designed in medical view. In general, our skin can only absorb 7% from common biochemistry skin care products, but the data reaches up to 13% for traditional Chinese medicine skin care products. When making the cosmeceuticals, rotovap extraction is a necessary procedure, it needs to dissolve the medicine, and make cosmetics and medicine has the same viscosity.

Rotary evaporator uses: R&D in medicine

Every medicine laboratory has a set of rotary evaporator, sometimes it is more frequently used in a medicine lab than in a chemical lab. The rotovap extraction and distillation are necessary steps to develop a kind of medicament.

Rotary evaporator uses: water quality monitoring

Water quality testing means testing the total dissolved solids(TDS) in water, if we want to analysis 1 liter water that contains impurity, now a rotary evaporator is used to evaporator most clean water, so that we can accurate calculate the impurity.

Interested in our products? Please contact rotovap@lanphan.com

Which One Should I Choose? Rubber Hose or Metal Flexible Hose?

Rubber hose and metal flexible hose are two types of fluid line that installed in pipelines to delivery medium. The purpose of this article is to help you determine which one is best for your application, rubber hose or metal flexible hose? Let’s see their strengths and weakness.

stainless steel hose

A stainless steel hose or metal flexible hose is manufactured by welding the steam and butt of stainless steel hose ends together, and welding the fittings onto stainless steel hose. A stainless steel hose has excellent heat resistance and high pressure rating, it shows great adaptability when applying to high pressure and heat pipelines. Welding is the key procedure in the manufacturing of a stainless steel hose, if welding in a wrong way, a leak path can be created and bad for pipeline operation.

A rubber hose is manufactured by rubber material combining with cord fabric line inside the rubber layer. Rubber hose is easier to set in complex working condition since it has good flexibility. Rubber hose is convenient for replacement and its pressure range ratings up tp 10000 psi. Rubber material has good vibration resistance, thus rubber hose is best for pipelines that require resistance to vibration. However, rubber hose is not suitable for high pressure and strong external force pipelines. Comparing to metal flexible hose, rubber hose has shorter service life, it needs to be replaced in regular time.

In modern fuel gas piping system, more rubber hose is replaced by stainless steel hose. Because stainless steel hose is more safe and durable in use. Please enquiry at best@lanphan.com or call 86-371-67447999.