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NYP high viscosity gear pump seal selection of the whole solution

2014/4/28      view:

NYP high viscosity gear pump seal selection of the whole solution
Selection NYP high viscosity gear pump seals , working conditions must be considered in order to select the appropriate form and seal materials, installation structure. To consider working conditions generally include: temperature, pressure , medium. Other features of the device itself also need to combine to consider selection.

On temperature , operating temperature range of materials such as NBR is generally -40 ~ +120 ℃. It is necessary to consider beyond 120 ℃ FKM , and even the PTFE material . Relatively rare low temperatures , in general, in the case of -20 ~ -40 ℃ to consider the use of cold NBR, NBR material is generally in the low temperature will cause the material to harden , resulting in leakage, such as in winter in the northern railway locomotive it is often such problems .

As the pressure, the selected form to affect the seal . In general, in the low- pressure selection of rubber or PU seals will not be a big problem. But to consider the issue of a shock pressure , such as construction machinery startup, shutdown when its impact is much greater than normal operating pressure of the pressure , so the pressure will often choose up 70MPA impact resistant squeeze gap HBY or SPGW done mainly seal. PTFE seals is also commonly used in combination an option .

The problem is relatively simple media . Just need some special attention to small problems, such as metallurgical industry, often using water tanks - glycol and phosphate ester hydraulic oil. Sometimes though temperature is not high, but still have to be very careful choice of materials , hydraulic oil when the latter still have to choose FKM.

Selection of the seal is important , or the device itself must be combined with selected conditions . For example , you need responsive, precise control of the course, choose Lancaster closure Grameen circle. Require high reliability, often choose Hunger 's GD1000K series or NOK in SPGW. As another example, when the work of construction machinery field work often has an impact and cold weather , it 's dust ring exposed metal skeleton will be chosen so as not to cause the loss.

Cylinder, piston ring compressor , high pressure seal, and a variety of scientific instruments in which the pump seal structures are required to meet specific requirements .

All these different terms , and I welcome you to communicate seals Selection

NYP high viscosity gear pump mechanical seal what is common sense ?

Mechanical seals are precision , one basic element of mechanical structure is more complex , is a key component of various pumps, reaction synthesis reactor, turbine compressor , submersible motors and other equipment . Sealing performance and service life depends on many factors , such as the accuracy of selection, the machine, such as the right to install and use .

First, the selection method

Mechanical seal according to the working conditions and the nature of the different media , with high temperature , low temperature mechanical seals , high pressure , corrosion-resistant mechanical seals , mechanical seals and resistant granular media adaptation mechanical seals easily vaporized light hydrocarbon medium , etc., should be based on different select the usefulness of different structural types and mechanical seal materials. Selection of the main parameters are: the seal chamber pressure (MPA), fluid temperature (℃), working speed (M / S), the characteristics of the fluid and the effective space to install seals and so on.

Mechanical seals have any knowledge of the basic principles of selection are:

1 , according to the body cavity pressure seal , the seal structure is determined using balanced or unbalanced , single face or double , etc. .

2 , according to the pace of work , determine the use of rotary or static , hydrodynamic or non -contact type .

3 , depending on the temperature and fluid properties to determine the friction and auxiliary sealing materials, as well as the right choice for lubrication, washing, heat , cooling and other mechanical seal cycle protection systems.

4 , according to the space available to install seals to determine multi- or single- spring or spring wave springs , built-in or externally mounted .

Two , NYP high viscosity gear pump installation and use requirements of mechanical seals

Knowledge of a mechanical seal . Mechanical seal machine accuracy requirements ( to pump mechanical seal , for example)

( 1 ) radially mounted mechanical seal parts of the shaft ( or sleeve ) does not exceed the maximum runout tolerance of 0.04 ~ 0.06MM.

( 2 ) rotor axial movement of not more than 0.3MM.

( 3 ) locating and sealing cap seal chamber face a combination of shaft ( or sleeve ) surface runout tolerance does not exceed the maximum 0.04 ~ 0.06MM.

Mechanical seals knowledge 2 . Confirmation of the seal

( 1 ) confirm the installation of the seal is consistent with the requirements of the model .

( 2 ) carefully before installation and assembly diagram control , the number of parts are complete .

( 3 ) the use and transmission of the coil spring mechanical seals , whose spring has left and right hand of the points, always subject to spin the shaft choice . 3 , the installation

Installation with mechanical seal type , the type of machines differ , but the installation of almost all essentials the same installation steps and precautions are as follows :

( 1 ) determine the size of the installation

When installed, should use the manual or product samples to ensure the mechanical seal mounting dimensions.

( 2 ) Before loading , the shaft ( sleeve ) , the gland should be no burr, bearing in good condition ; seals, shaft seal cavity , the gland should be cleaned. To reduce friction, mounted on the shaft to the mechanical seal parts coated with a thin layer of oil for lubrication, considering the compatibility of the rubber O -ring , oil , if not , can be coated with soap and water. Floating -mounted stationary ring structure with no anti-rotation pin , not oiled , you should dry loaded gland.

( 3 ) first stationary ring mounted on the shaft along with the gland , be careful not to collide with the shaft , and then move into the ring assembly . Spring seat or seat drive set screws should be tightened evenly several times .

Before the gland is not fixed , he pushed compensate for axial compression ring , the ring can automatically release the compensation bounce without catching phenomenon , then the gland bolts evenly tightened.

4, NYP high viscosity gear pump use

( 1 ) When the transmission medium temperature too high , too low, or contains foreign particles , flammable , explosive, poisonous time , must take appropriate barrier seal , washing, cooling, filtration and other measures.

( 2 ) before running hand drive cars , pay attention to the torque is too large , with or without a collision and unusual sounds.

( 3 ) Note that rotation, whether the coupling , the bearing parts of the lubricant additive is appropriate piping is correct.

(4) The first run media , the cooling water valve opens , check the seal cavity full exhaust gases to prevent static caused by leaks, then start running.

( 5 ) After the drive is working properly and stable , abnormal torque caused by the presence or absence due to shaft rotation , as well as abnormal noise and overheating.