Spring hanger selection and design guidelines for a Pipes

Spring hangers are an integral part of Piping Industry. The use of spring hangers for supporting pipe weights are common to every piping engineer in the industry. When some

Spring hanger selection and design guidelines for a Pipes

Spring hanger selection and design guidelines for a Pipes

rigid supports are not taking load due to its thermal movement or rigid supports are creating bad effect to equipment connection Piping engineers suggest the use of a spring hanger to share some of the loads and to keep the piping system safe and efficiently working. Selection of the appropriate type of pipping spring hanger support for any given application is governed by the individual piping configuration and its requirements. In general there are two types of spring hangers, that is

 a) Variable Spring Hanger- Loads vary throughout its operating range and

b) Constant Spring hanger: Load remains constant throughout its operating range.

The following information will provide you a simple guideline for the right selection of both Variable and constant spring hanger while analyzing a piping system

  • Determine the hot load required and the pipe movement in a given setup or industry.
  • Always estimate the travel range from the given catalogue.
  •  Select a mid-range spring size for the equipment that has hot load within the working travel.
  • Always ensure that the cold load lies within the working range of the spring.
  • In case the Cold load lies beyond the working range in the selection chart, then select higher spring size or the next travel range.
  • Check the variability in the selected spring hanger. Usually for non-critical applications and systems, the variability is limited to 25% throughout the total travel. But for critical systems such as steam connections, terminating at turbines and pipes connected to rotating equipment like compressor, the variability is limited to 10%.If the variation exceeds the allowed number, choose higher size spring or smaller spring rate within the same load range.
  • Select the type and check the feasibility of the spring depending on space available and type of structure available.
  • Always select pipping spring hangers that are resilient to liquid like water acid or any external environment exposures.

Important things that you need to know about Anti-Vibration Pads for Machinery

What are Anti-vibration pads?

Anti-Vibration Pads are tools or devices used for vibration isolation of industrial machines. These devices are used for elastic mounting of machines, generators, pumps, electrical panels, compressors, and engines and many other such industrial machinery and ANDRE-Pads-RCMP-Series (3)equipment’s. The Anti-Vibration isolation pads help dampen the vibrations generated in the machine frame. These Anti-Vibration Pads are suitable for damping vibrations in machines weighing anywhere from 10 Kgs to 20,000 Kgs. On mounting the machines on these Anti-Vibration Pads, the vibrational movements are damped by the vibration damper pads. These vibration Pads for machines are designed to absorb vertical and horizontal vibrations coming from these machines.

Why are these vibration absorbing pads required and where are they used?

  • Anti-Vibration rubber Pads are useful tools in vibration damping, especially in equipment’s like compressors, pumps, engines etc.
  • Vibration Pads are also used in Centrifugal Machines to reduce vibrations.
  • Anti-Vibration Pads greatly reduce vibrations generated from Pumps / engines.
  • Vibration absorbing pads are also widely used in HVAC equipment’s for controlling vibrations
  • Engine radiator is mounted on Anti-Vibration rubber cork pads for best performance and long-life.
  • Industrial Exhaust systems produce high frequency vibration due to large gas exhausts. Hence they should be mounted on Anti-Vibration Pads for better damping of the machine.
  • Air conditioning equipment’s are mounted on Anti-Vibration Pads to reduce vibrations and noise from entering building structures.
  • For equipment’s like compressed Air/fluid transfer pipes that produces massive vibration are mounted on pipe hanger anti-vibration pads.
  • Also, to isolate external vibrations, Testing Machines and equipment’s are installed on Anti-Vibration pads.

 How to select the right Anti-vibration Pad for your machine?

  • Identify the machines in your industry that require noise and vibration damping equipment’s. Depending on the application, select among the various High grade neoprene pads, Tico anti-vibration Pads, rubber cork pads and anti-vibration sheets that best suits the machine.
  • Select the number of mounting locations required for the machine. The number of mounting locations is usually the number of machine feet or machine foundation bolts supplied along with the machine.
  • Compute the total weight of the machine and calculate the static and dynamic weight of the machine at each mounting point. This helps in deciding the right anti-vibration pad for your application.
  • Always look for any special parameters required for the Anti-Vibration Pads. For instance, the Anti-Vibration Pads can be specially designed for mobile applications, the Anti-Vibration Pads could be designed for resistance against exposure to weather and climatic conditions, the Anti-Vibration Pads can be made rigid or extra soft as per the application, the Anti-Vibration Pads can be manufactured for resistance against exposure to water, acid, oil or diesel flooding, the Anti-Vibration Pads can be designed for applications with stiff grouting and movement constraints.
  • There are different type of anti-vibration pads available. So, depending on the whether the machine is on the ground or suspended floors, one can accordingly select the right anti-vibration pads to suit the application requirement.
  • Specify the bolt-size or mounting requirements for the machine where the Anti-Vibration mounting Pads are to be used.

Seismic isolators to your rescue against natural forces

Natural calamities like earthquakes can strike anywhere in the world. Mankind has been making every possible effort to reduce the impact and damage caused by Nature. A lot of research goes into the study of the seismic activity and its impact on the buildings, equipment, and machinery. Andre HVAC International Inc. has been consistently involved in the supply of seismic spring mounts, hangers, isolators, and vibration dampers. The specialized seismic isolation equipment is also sourced by them from established companies. Let us look at some of them:

Korfund Vibration isolators: Korfund Dynamics is a company which has been delivering high tech solutions to the power generation, construction equipment, marine, and industrial machinery conglomerates for more than hundred years. Its range of products includes shock, vibration and structure borne noise isolation products. The Korfund vibration isolation systems comprise of spring, elastomer, cable and pad type isolators. The latest offerings of Korfund isolators are rugged, lightweight, low profile installations. Andre HVAC International Inc. has taken the onus of supplying the Korfund vibration isolator products as per customer specific requirement.

Caldyn isolators: California Dynamics Corporation or Caldyn is another reputed supplier of vibration isolation and seismic protection products. The product range includes neoprene isolation pads and mounts, spring vibration isolators and restraints, spring and acoustical hangers to name a few. Caldyn has commitment towards protection from earthquakes and noise control. That is one of the prime reasons for Andre HVAC International Inc. to make the Caldyn isolators and seismic restrained isolator product available for its customers.

Restrained seismic spring mount: During the time when a seismic event occurs the equipment and machinery on the floor or on stands are subject to high G forces. A lot of factors related to the installation of the machine come into play at such times. A normal vibration damping spring mount may not be able to sustain the high G forces in all directions. The restrained seismic spring mounts from Andre HVAC are specifically designed and seismically rated in order to have all directional restraint with materials like neoprene and springs.

Seismic spring: The seismic springs form a part of the seismic vibration isolators. The spring elements are selected to provide the static deflections as per the vibration isolation schedule or as specified by the customer. Springs are normally color coded in order to indicate the deflection characteristics and load capacities. The seismic springs must have a lateral stiffness 1.2 times the rated vertical stiffness and must withstand 50% overload. The Andre HVAC seismic springs are tested and rated as per the seismic standards and can be comfortably installed by the clients

We believe that you as a customer face a number of hurdles related to vibration and control in your businesses. Andre HVAC International Inc. provides anti-vibration products and services in a wide range and variety so as to suit the customer needs.  Andre HVAC offers quality, reliability, quick delivery with service and support. Its products are recommended by consultants and architects around the world.

Seismic mounts an ideal isolation equipment of industrial machine against seismic force

Integrated seismic mounts are devices designed for mechanical equipment to combine with spring mount vibration isolation with multi-directional flexible restraint to limit equipment movement under heavy seismic disturbance. In normal operating environment, the mountings provide vibration isolation generally equivalent to open spring mountings but, when subjected to physical displacements such as those generated by seismic forces, the equipment motion relative to the supporting structure is restricted. At the maximum restraint capacity of each mounting type movement is limited to less than 12mm along any given major axis.

So, on selecting the right integrated seismic mountings it will allow conformance to the design requirements and other International Seismic Codes. Andre HVAC offers a wide range of seismic spring mounts for a full range of applications, as well as a rubber seismic mount, and independent seismic restraints. Also available are cable restraints, which are used in conjunction to spring or rubber hangers for the seismic restraint of suspended piping and equipment.

Selecting the correct seismic mount.

It is always critical to select the right seismic mount for your industrial application for effective isolation of vibration caused due to any seismic force. The dynamic factor needs to be taken into account while selecting for a seismic mounts. The seismic mounts are required to conform to AS 1170.4, for NZS 4219 the restraint capacity needs to be confirmed for the specific application.

Seismic mounts and restraints help control the motion of equipment, piping and ductwork during a seismic event. Proper sizing and placement of seismic restraints and accurate calculation of anchor bolt forces is critical in adequately restraining equipment against seismic effects.

Seismic mounts and restraints are designed in a way to provide the strength and isolation that is necessary to maximize the chances of these systems remaining intact and attached to the building structure. It is advisable that you consult with good engineers and architects to determine the best possible seismic solutions for your industrial application.

Seismic rated mounts and restraints that control the motion of equipment, piping and ductwork during a seismic event possess the following features

  • Rugged steel housing designed to handle high wind and seismic forces.
  • Housing serves as blocking during equipment erection.
  • Top plate are welded or bolted to equipment, allowing flexible design options.
  • Housing heights are identical within each series.
  • Easily accessible bolt holes permit easy installation.
  • Isolators are manufactured well to maintain consistent quality.
  • Powder coated housings and springs offer outstanding corrosion resistance.
  • Springs are easily accessed for replacement if loads change.
  • Color-coded springs offers proper identification of load capacity and simple inspection.
  • Elastomeric acoustical cup allows for effective and efficient vibration isolation.
  • Spacer block allows for ease of installation by maintaining the installed height of the equipment and setting the proper air gap for seismic code compliance.

All seismic isolators are manufactured by Andre HVAC are of high quality material. The standard finish on the housings and springs is powder coating and all hardware within the mounting are well coated for better resilience against environment exposure and galvanized for superior corrosion resistance.

Keep the vibrations out with the wire rope isolators

Equipment and machinery in the industrial environment are subject to vibration and shock. Whether it is mechanical, electrical or electronic equipment, vibration and shock lead to Keep the vibrations out with the wire rope isolatorsshortening of life of the machinery. At times the equipment suffers withdrawal from service due to the severe impact of vibrations. This premature failure is a result of stress due to repeated load or fatigue or a combination of both.

The Andre HVAC wire rope isolators come quite handy in preventing such conditions. They are designed to take care of shock and vibration issues in most of the situations. Your HVAC equipment gets protected as the wire isolators do not allow the vibrations and shock to get transferred.

Applications:

The wire rope isolators are ideally suited for heavy duty machinery like generators, HVAC equipment, motors, pumps and blower fans. Each wire rope mount comes with softened non-linear stiffness. The maximum dynamic displacement is over 70 per cent of the space taken up by the mount. As there is an increase in displacement the dynamic stiffness of the wire isolator decreases.

Wire rope selection:

In the wire rope mounts the key is to select the wire rope with proper characteristics, which include the wire length, number of strands, wire diameter, wire rope twist and number of wire ropes per section. The wire isolators are capable of providing a damping between 5% and 20%. You can go in for a larger diameter rope for maximizing the damping, while the wire rope isolator becomes stiffer. The basic framework of the Andre HVAC wire rope vibration isolators consists of a heavy duty category stainless steel interweaved wire rope and retaining bars made of aluminum alloy. The wire rope is threaded through the retaining bars to form a solid combination.

Space constraint:

The compact wire rope isolators are passive in nature and occupy very little space. When there is a space constraint you can go in for the compact wire rope isolators or the circular wire rope isolators. These wire isolators provide the same vibration and shock isolation capabilities as the normal wire rope mounts, but they are just smaller in size. They hardly need any maintenance and are capable of operating under a wide range of temperatures and corrosive environments.

Environmental impact:

While the temperature range is very wide, from -200o F to +650oF, the corrosive environments like humidity, ozone layer, nuclear radiation, grease and oils have almost nil effect on the cable isolators. They have a long life span and can take care of elastic displacement in every dimension, thus allowing for vibration isolation in multiple directions. The Andre HVAC wire rope isolators for vibration damping can be installed in a number of ways.

Other applications:

The defense shock mounts are ideal for all types of military applications, avionics, marine equipment, and drones to name a few. They are suitable for transportation of missiles and satellites, protection for navigation and launching systems as well as large scale construction.

The Andre HVAC brings to you the Enidine wire rope isolators which possess environmental stability and are not affected by oils, chemicals, abrasives, ozone, and temperature extremes. They are suited for the applications that demand the highest level of quality, performance and ruggedness.

The compact wire rope isolator solutions in space constrained applications

When the requirement of vibration isolation of electronic components was felt, the industry first came up with elastomers. These were selected on their properties of vibration The compact wire rope isolator solutions in space constrained applicationsdamping and ease of fitment in limited space. But unfortunately, the elastomer was not able to cope up with the temperature extremes and harsh environments. It was also not providing the solution to simultaneous shock and vibration.  The wire rope isolators were too big for the electronic applications and hence an alternative was worked out. That is when the compact wire rope isolators came into being.

The design aspect:

The compact wire rope isolators are designed for simultaneous or separate vibration and shock mitigation in the areas where there is a space constraint. The compact wire rope isolators have a symmetrical design and a one point installation. Thus, they provide multi-axis isolation which is quite consistent. Since the compact isolators are small in size they are specifically utilized for isolation of critical individual components rather than the system as a whole. Thus, the compactness makes the isolators economical and also allows for high performance system designs.

The properties:

The compact wire rope isolators are made up of 304 stainless steel wire rope and 6061 – T6 aluminium alloy retaining bars. The wire rope comprises of a number of high tensile wire strands which are braided together. The metallic components are unaffected by ozone, chemicals and oils. In fact, the compact wire isolators can withstand corrosive and hostile requirement also.  They also withstand extreme temperatures from -100oC and going up to 250oC.The standard products from Andre HVAC compact wire isolators accommodate the load from 5 to 35 Kg. The products also conform to a number of military standards and industry specifications.

Impact load performance:

The maximum dynamic displacement utilizes 70 per cent of the space taken up by the compact wire rope mount. The dynamic stiffness decreases with the increase in displacement. The resilience is shown by the compact wire rope isolator in case of a shock loading. The wire isolator does buckle under the load but without getting permanently deformed. It is able to spring back into position once the shock load is avoided.

More properties:

The compact wire rope isolators depict non-linear characteristics in the stiffness properties. The smaller deflections which are normally linked with vibration isolation will have a dissimilar spring rate rather than the larger shock deflections. The damping offered by the compact isolator is to the tune of 5 to 15% depending on the size and input level. The multi-axis capability allows the wire isolator to undertake compression load, 45o compression/roll and fixed roll/ shear load with ease.

The industrial use:

The design of the compact wire rope isolators allows it to be used in a number of applications. In the electronic industry they used for CD-ROM drives and disk drives. The equipment like centrifuges and medical ventilators make use of the compact design. Besides them a number of other applications like audio-visual equipment, avionics, sensitive electronic equipment and small pumps and motors make use of the compact wire rope isolators.

The compact wire rope isolators from Andre HVAC are a versatile piece of equipment offering vibration and shock mitigation solutions.

Tackling vibration, shock, and noise through wire rope mounts

When the machines or equipment are operated they generate vibrations which get transmitted to the receiving structure which may be a floor, frame or a support. The vibrations result in unwanted effects in two domains. The first is the structure borne sound, due to the vibrations in the audible frequency range. The other is resulting from low frequency vibrations which lead to structural fatigue and failure. In order to reduce the vibration transmission the source has to be decoupled from the receiving structure. This is best achieved by the use of wire rope isolators.

Vibration, shock and noise

The use of wire rope mounts is traditionally done for providing insulation from low frequency vibrations. The wire isolators are also frequently used for shock isolation applications. However, of late there is a lot of interest in the use of wire rope vibration isolators for noise abatement, which is effective isolation within the audible frequency domain. Here the stiffness of the wire rope comes into play. Contrary to popular belief which favors metal springs, the cable isolators are also suitable for noise and vibration applications within the audible frequency zone.

Damping and amplitude

The wire rope isolators for vibration damping provide rather high damping just like rubber isolators. The reason for this behavior is due to the friction motion between the separate threads of the twisted wire rope. The stiffness is strongly dependent on the frequency but Tackling vibration, shock, and noise through wire rope mountsis independent with respect to the vibration amplitudes, within the audible frequency range. The wire rope vibration isolators depict a low stiffness for significantly high amplitudes in low frequency applications. Thus the behavioral patterns of the wire rope isolators are suited for vibration and shock isolation as well as for noise reduction in the audible frequency domain.

Impact load and shocks

The Andre HVAC wire rope mounts have a superior resilience. The systems have the ability and strength to restrain load under unfavorable conditions. They rapidly return to the normal operating position after repeated shocks. The wire rope isolators diminish the shock with minimum dynamic travel. Large deflections are required to bring the impacts of heavy shock loads within acceptable limits. The Andre HVAC wire isolators are having a sturdy design which does buckle under shock loads but does not deform permanently or bottom out.

Space limitations

The versatility of the wire rope vibration isolators can be gauged from the fact that it provides three-plane and all axis isolation. It can also be installed vertically, horizontally or laterally. The design strengths are responsible for the wire rope mounts to be installed in very compact areas. The compact wire rope isolators are specialized product offerings keeping the limited space requirements in mind.

Wire rope properties

The steel wire rope which is used in the threaded coil form in the wire rope mounts is strong, flexible and fatigue resistant. This property emanates from the wire construction which contains multiple strands of high tensile drawn wire. When the coil is bent or buckled under the load it has the elastic element properties just like a spring or rubber mount.

Passive vibration solutions through wire rope isolators

The vibrations can be mitigated through two processes. The first is the active vibration isolation. This process employs the use of electric power which is used for electronicPassive vibration solutions through wire rope isolators force cancellation through a number of sensors, actuators and control systems. However, most of the vibrations are dealt through passive vibration isolation. This process makes use of passive techniques like mechanical springs, elastomer pads and sheets etc. The wire rope isolators are categorised as passive vibration isolation techniques.

Application:

The passive vibration isolation is a vast subject in itself. Today, there are a number of passive vibration isolators that are used for a variety of applications. Civil engineering makes use of the passive isolation of structures from earthquakes, isolation of sensitive laboratory equipment from the ground vibrations etc. In the industrial applications the passive vibration isolators are used for pumps, motors, HVAC systems, and washing machines etc. The Andre HVAC wire rope mounts are highly effective in the mitigation of vibrations and shock.

Passive isolation working:

A passive isolation system like a wire rope mount contains mass, rope coil or spring and damping elements. The system moves as a harmonic oscillator where the coil stiffness and mass are responsible for generating the natural frequency of the system. The damping process results in the system losing energy and has a secondary effect on the natural frequency.

Understanding vibration:

Every piece of equipment on a flexible support system has its own fundamental natural frequency. When the equipment runs and generates vibration, the transfer of energy takes place most efficiently at the natural frequency. It is somewhat efficient below the natural frequency and at increasing efficiency above it. The ratio of the vibration of the isolated surface to that of the source is known as transmissibility. Vibrations can never be completely eliminated though it is possible to reduce them substantially. It is here that the Andre HVAC wire rope vibration isolators score over the competition.

The damping phenomenon:

Below the natural frequency the transmissibility ratio is around 1. It means that the vibration is passing through the system without getting amplified or reduced. The amplification happens at the resonant frequency. Damping is the process that limits the amplification. Any type of mechanical system in this world is likely to contain some amount of damping. It dissipates energy in the system, leading to a reduction in the vibration level and its transmission at the natural frequency. A passive isolator like the wire rope isolator for vibration damping can be viewed as a filter for vibrations.

Functioning:

The wire isolator normally functions in both the directions. It insulates the equipment from the floor vibrations and also does not allow the equipment vibrations to pass to the floor. Large HVAC systems which can cause vibrations in the building or room are isolated from the floor using the Andre HVAC wire rope isolator. There are multiple sources that can generate vibration. Depending on the requirement the multitude of vibration sources can be tackled for desired results.

Choose the right wire rope isolators for your HVAC requirements

Are you in the process of installing HVAC equipment in your home or for commercial use? The equipment could include air-handling units, heating and cooling coils, variable speed drives, fan coil units, chiller units, condensing units, indoor units, and dedicated outdoor air systems. Most of the equipment are motorized and generate a huge amount of vibration. These vibrations are transmitted to the mounting frame or floor to the recipient area.

Taking care of vibrations:

The vibrations which are in the low frequency range are the major cause for structural fatigue and failure. The best way to prevent the transmission of vibrations is to make use of wire rope isolators between the HVAC equipment and the receiving structure. The wire rope mounts are very effective in blocking the vibrations in both the directions. It means that not only the vibrations from the HVAC equipment to the support are mitigated, but the other vibrations from the support are also blocked from travelling to the HVAC equipment. Thus, the wire isolators also protect the HVAC equipment from damage.

Handling space limitations:

If you are using the equipment inside the house and there is a limitation of space, you can go in for the compact wire rope isolators. They have a symmetrical design and provide a multi-axis isolation. Since they are small in size it is recommended to use separate compact wire rope isolators for each piece of equipment rather than for the whole HVAC system. The best part is that you can mount these cable isolators along any axis in the bottom or traverse position. That proves how versatile these wire rope vibration isolators are.

Simplicity of design:

The Andre HVAC wire rope isolators are very simple in design. They have the two primary components. The first one of these is a steel wire rope made up of multiple strands of high tensile steel wires braided together to give it strength and fatigue resistance properties. The other part is the aluminum alloy retaining bars. The wire rope is coiled through the set of the retainer bars and crimped using a patented design. When one has a look at the simple design of the wire rope mounts, it makes him wonder how it mitigates the vibrations so well.

Tackling harsh environments:

In case you are planning to mount the HVAC equipment in an area where there are chances of chemicals and oils coming in contact with the wire rope isolator for vibration damping, you can opt for the Enidine wire rope isolators. They not only handle harsh and corrosive atmospheres but also large amount of temperature variations also. Thus the Enidine wire rope isolator falls into the category of fit and forget wire rope vibration isolators.

The Andre HVAC wire rope isolators resolve the shock and vibration issue in virtually any application. They are especially suited for the HVAC equipment. The standard wire rope mount designs can be selected by the use of simple formulas, while the customized options are made available as per requirement.