mechanical seal installation made in china

John Crane has operated in China since 1986, giving local customers access to a wide variety of mechanical seals and aftermarket services. The latest investments are part of the company’s strategy to continue building infrastructure to support local customer demand across Asia and other targeted high-growth markets. Among the investments are:

In addition, the company is increasing gas seal capabilities at the Tianjin, China facility to give the local market access to gas seal engineering expertise, and manufacturing, service and repair capabilities.

John Crane www.johncrane.com is a global leader in engineered technology, supplying engineered products and services to energy services customers and other major process industries. The company designs and manufactures a variety of products including mechanical seals, couplings, bearings, filtration systems and artificial lift equipment. John Crane employs about 6,900 people and has more than 230 sales and service facilities in 50 countries. Fiscal year 2014 revenues were $1.5 billion. It is part of Smiths Group www.smiths.com, a global leader in applying advanced technologies for markets in threat and contraband detection, energy, medical devices, communications and engineered components.

Supplier of, Actuators, Agitator Assembly, Air Regulator, Back Stop Clutch, Bearing Housing, Bearings, Blowers, Boards (Electronic), Boilers, Bursting Disc for RO membrane, Bushing HV and LV, Cards, Carrier Bridge, Cement Kiln, Cement Mil, Convertors, Conveyors, Couplings, Cranes,Crushers, Cylinders, Hydraulic, Pneumatic, Dampers, De ionizer, Debris filter with ball collector, Displays, Expansion Bellow, Fan, Blower, Filter Cleaning Controllers & Accessories, Filters, Elements, Cartages, Fuses, Gantry Cranes, Gauge Glass, Gauges, Gear Boxes, Gears, Header Tank Systems, Hot air industrial oven, Large Size Generators, Level Indicators, Load cells, Measurement, Pressure and Temperature, Mechanical Seal, Modules, Oil conservator, Pneumatic Controllers, Positioners, Power Supply,Pumps, Reducers, Relay, Repair Kits, Sample Cell

Scraper, Seals, Sensors, Shafts, Soft Starters, Stacker & Reclaimer, Surge Arrestors, Switches, Thermocouple, RTD, Thyristor, Transducers, Transformers, Transmitters, Turbines, Valves, Variable Frequency Drive

The main parameters of mechanical seal selection: seal cavity pressure (MPA), fluid temperature (℃), working speed (M/S), fluid characteristics, and effective space for installation of the seal.

According to different working conditions and media properties, mechanical seals include high temperature and low temperature resistant mechanical seals, high pressure resistant and corrosion resistant mechanical seals, particle resistant mechanical seals and mechanical seals suitable for light hydrocarbon media that are easy to vaporize.

1: According to the pressure of the sealed cavity, it is determined that the sealing structure adopts balanced or unbalanced, single end face or double end face, etc.

3: According to the temperature and fluid properties, determine the friction pair and auxiliary sealing materials, and correctly select the mechanical seal circulation protection system such as lubrication, flushing, heat preservation, and cooling.

4: According to the effective space for installing the seal, determine the use of multiple springs, single springs or wave springs, built-in or external.

(3) The maximum runout tolerance of the positioning end facing the shaft (or sleeve) surface of the sealing cavity and the sealing end cover shall not exceed 0:04～0:06MM.

(3) The mechanical seal is driven by a parallel spring. The spring can be divided into left and right rotation, which must be selected according to the rotation direction of the shaft.

The installation method varies with the type of mechanical seal and the type of machine, but the installation essentials are almost the same. The installation steps and precautions are as follows:

(1) Determination of installation size When installing, the installation size of the mechanical seal should be ensured according to the product"s instruction manual or sample.

(2) Before installation, the shaft (sleeve) and gland should be free of burrs, and the bearing should be in good condition; the seals, shaft, seal cavity, and gland should be cleaned.

In order to reduce the friction resistance, the part where the mechanical seal is installed on the shaft should be coated with a thin layer of oil for lubrication. Taking into account the compatibility of the rubber O-ring, if it is not suitable to use oil, it can be coated with soapy water.

(1) When the temperature of the conveying medium is too high, too low, or contains impurity particles, is flammable, explosive, or toxic, corresponding measures such as sealing, washing, cooling, and filtering must be taken.

(5) Before operation, first open the medium and cooling water valve, check whether the gas in the sealed cavity is completely discharged to prevent leakage caused by static pressure, and then start the operation.

Install mechanical seals onto shaft. And fasten bolts on the flange,evenly(Don’t fasten one bolts very deep at first time, you need fasten them one by one, and strength bigger and bigger, untill all bolts fasten together)

Input cooling water before operate mechanical seal. Ensure cooling water normal operation. The pressure of cooling water should be more than media 1 bar. For example, if pressure of your media is 0 bar, the cooling water should be 1 bar.

Major for water pumps and circulation pumps Working Conditions: Pumps:Water pumps, circuation pumps,etc. Temperature:-20 o C~200 o C Pressure: ≤0.8Mpa Speed: ≤ 10 m/Sec Combined Materials: Stationary Ring(Carbon/SiC/TC) Rotary Ring(Ceramic/SiC/TC) Secondary Seal(NBR/EPDM/Viton) Spring and Punched Parts(Steel) O-Ring Mechanical Seals Type ST155 Equivalent to Vulcan Mechanical Seal Type 13 Single Face Unbalanced Seal Conical Spring Fixed Rotation Direction

1. Take out the mechanical seal to be installed from the packing box and place it on a clean surface, protect the sealing surface, and arrange all labels and certificates for inspection;

2. Check the model, specification and material certificate of the mechanical seal, the number of parts, whether the pair of rotary face and stationary seat meet the requirements of the drawings, and whether there are identification marks of the manufacturer on the parts;

3. Check the surface quality of each part, especially whether the mechanical seal rotary face and stationary seat face are damaged or scratched. If damaged, it must be repaired or replaced. The surface of the parts must be cleaned. Especially the mechanical seal rotary face and stationary seat face can be applied by a layer of oil;

4. Check the water pressure test certificate of the graphite ring, the glass-filled PTFE ring, and the assembled rotary face and stationary seat . If there is no pressure test certificate, a water pressure test must be done before installation. The test must be in accordance with the first section of Chapter VI. Regulations;

5. For mechanical seals driven by parallel coil springs, pay special attention to the direction of rotation of the spring. The direction of rotation should be the same as that of the shaft so that when we rotates it in the right direction,the spring will be the tighter and tighter .That is, in the angle from stationary seat to the rotary face according to the shaft rotation direction,a clockwise direction requires a right-handed maneuver, and vice versa.

6 Check the axical displacement, shaft radial play, related perpendicularity, concentricity, surface roughness, matching size and requirements for the shaft coupling and so on. They are all technical requirements for the host machine installed with the mechanical seal.

（1）axical displacement value：no more than 0.1mm, generally between 0.025~0.1mm. If too big, the specific pressure of the mechanical seal spring will be unstable, causing the wear or leakage of the seal face due to the vibrating of the shaft. The seal is damaged, which is more obvious in the graphite ring. In addition, because of the too big axical displacement value, partial corrosion, erosion or wearing will take place at the contacting part between the mechanical seal and the shaft (or sleeve). PTFE sealing ring are less elastic than rubber counterparts and thus more affected. Therefore, the axical displacement value needs to be changed from the original ±0.5mm to no more than 0.1mm, which can reduce the damage caused by the excessively big deviation. On the other hand, if the axical displacement value is too small, less than 0.025mm for example, it will have an adverse effect on the bearing.

In fact, the axical displacement value is also related to the shaft speed. The following figure picture 1 shows the relationship between the axical displacement and the shaft speed, which can be used for reference during installation.

（2）Allowable value of shaft radial play: Excessive shaft radial play will cause the jittering or deviation of the shaft,thus increase the seal contact surface, reduce lubricating film, and accelerate wear, which is detrimental to the sealing performance and service life of the mechanical seal. Therefore, JB4 127-85 stipulates：

(3) The verticality between the shaft and the stuffing box: no more than 0.1mm, generally 0.08mm. If the value is too big, the cover will tilt up and the mechanical seal will vibrate, and the wall surface will have uneven specific pressure and liquid film loss. Then erosion and abrasion will occur. The vibration of the mechanical seal will also wear out the driving pin, and finally make the sealing performance and service life unsatisfactory.

According to the inspection of the mechanical seal, the verticality between the shaft and the stuffing box is related to the shaft diameter and the shaft speed. It is also related to the compression method of the gasket used for sealing when the cover is installed. The use of unilateral compression will cause leakage.

（4）Concentricity between the shaft and the stuffing box of the mechanical seal : within the sliding speed V=25m/s, make sure the concentricity does not exceed 0.2mm, generally 0.125-0.2mm.（see following pictuture)

(6) Pump coupling requirements: The centering of the drive part is extremely important, because the side face runout and radial play of the coupling, the concentricity and the size of the cross-sectional gap will affect the life of the mechanical seal, thus requires checking regularly. The installation requirements of the coupling are usually stated in the instructions provided by the machine manufacturer.

The inspection required for couplingment should be carried out before the installation of all pipeline joints, otherwise, the centering work will be incomplete.

(1) Determine the installation position of the rotating parts on the shaft according to the mechanical seal assembly drawing (according to API-610, the contract materials include the operation and maintenance manual of the pump and the mechanical seal, and the separate drawing of the mechanical seal).

(2) Draw a line on the shaft to mark the position of L, if you are disassembling the machine, mark the original installation position on the shaft with a line. Then it will be easier to install the mechanical seal again.

(1) First install the anti-rotation pin1 in the pin hole of the sealing cover of the mechanical seal. Regardless of whether the vertical or horizontal anti-rotation pin is press-fitted, pay attention to the depth of the inserting, so that the prolonged pin should not touching the bottom of the groove of the stationary seat （holder）or the shaft surface.

(3) Put the stationary seal ring2 on the stationary seat3, and align the groove of the stationary seat with the anti-rotation pin1 in the cover10 , and push it evenly into the cover 10 of the mechanical seal.

(1) Place the spring adapter 4 of the mechanical seal up and flat, and then put the multiple springs 5 into the holes of the spring adapter, not skewed.

(2) Put the rotary face’s sealing ring 6 into the rotary face 7, and then put the pressure ring 8 on the rotary face of the mechanical seal . Note that the pressure ring should press the sealing ring 6.

（3）Put the pressure ring, the sealing Ring of the rotary face and the rotary face into the spring holder 4 of the mechanical seal together. Note that the groove on the outer diameter of the rotary face should be aligned with the protruding part of the spring holder.

（4）Put the spring holder together with the spring, pressure ring, rotary face and its seaingl ring on the marking position on the shaft of the mechanical seal, and then fix the rotating part on the shaft with the fixing screw 9.

Regarding the top compression amount of the spring, foreign drawings set it to be 4mm, and domestically it is generally 4~6mm, depending on the size of single spring, multiple springs and springs of the mechanical seals.

After the rotary face is installed, it must be able to move flexibly on the shaft of the mechanical seal. After the rotary face is pressed against the spring, it can automatically spring back.

（6）After the final assembling of the mechanical seal, check whether the auxiliary equipment is normal, check whether the cooling, circulation, ventilation, discharge, blocking and other pipeline joints are connected correctly. It is required that the inlet of the steam drop pipeline is at the upper part and the outlet the lower part; the cooling pipe inlet is at the lower part and the outlet at the upper part. After checking by craning, it should be light and flexible without jamming. Under normal circumstances, the radial runout of the shaft should be checked after the final assembling, and then it should be delivered to use after the static pressure test and a period of running-in.

The disassembling sequence of the mechanical seal is opposite to the installation sequence. It is strictly forbidden to use iron wares to knock it out during disassembling of the mechanical seal. It is best to use a special tool to disassemble in order. If there is dirt on the sealing element or the coagulant is dried up, the dirt should be cleaned before disassembly.

Established in 2006, Trelleborg Sealing Solutions in Shanghai is a full service manufacturing facility producing Slipper Seals in PTFE, PU, PEEK and other advanced plastics, Turcon® Variseal®, Orkot® products, PU seals, O-Rings and Airframe Seals. Our products can be found across every major market segment, including industrial, automotive and aerospace. We offer a wide range of standard catalog products. In addition, custom solutions can be tailored to satisfy special customer needs.

The time it takes to install a Valmet Mechanical Seal is the same as it takes to change a wear sleeve in an existing packing box, approximately 10 hours. The existing water system used for the packing boxes can be used again for the mechanical seals. An additional water filter may be necessary, depending on the quality of the water.

Valmet offers an exchange system for our mechanical seals which means easier handling and reduced costs. By using the exchange system the customer always receives a complete unit reconditioned and upgraded to the latest design. The trade-in unit is disassembled and inspected. Worn parts are reconditioned or replaced. The fixed price presumes that all vital parts of the trade-in unit can be reconditioned. If main parts must be replaced with new parts then the price is adjusted accordingly. The reconditioned trade-in unit become the property of Valmet and stored for the next customer.