What are the centralizers for pipe welding and how best to use them. Types of centralizers for pipes Pros and cons

A prerequisite for pipe-laying work is the presence of a high-quality weld. To achieve this result, centralizers must be used.

The effectiveness of the devices is especially appreciated by professional craftsmen who carry out main and local pipeline work, since it is quite difficult to determine by eye whether the edge of one pipe will coincide with another.

The Pipe Welding Centralizer is a special fixture whose main function is to ensure that the two edges of the required parts are properly aligned, but not parallel, before starting to weld them.

Use of a centralizer for pipe welding.

Thanks to this procedure, the size in place is stable, which allows mechanization of the process. In addition, with the use of a centralizer, there is no difference in internal diameters at the seam.

Due to this, turbulence does not occur in the flow of the working medium during pumping through the pipeline. The drag coefficient also decreases. The result is a sufficiently powerful operation of the pump in the main pipeline.

Any design of the centralizer to weld the pipeline must have:

1. Reliable fixation of all welded parts with each other.
2. Precise connection at the junction.
3. Convenient installation and dismantling.
4. Long-term, without the influence of external factors or frequency of operation.

Types of centralizers for welding

There are several ways to classify centralizers in order to weld the pipeline. Their classification into types consists in the division according to fixation and method of attachment.

Centralizer for welding.

In the first method, the equipment is divided into internal and external:

1. An internal centralizer is attached inside the elements to be welded to fix the pipe or other material in the required position.
   Internal pipeline centralizers are also used for large diameters. They have a complex structure and imply the presence of an additional hydraulic pump, engine and special mounting systems.
2. The external centralizer goes around the seam from the outside of the pipe.
   It looks like a large clamp for a universal product. Differs in simplicity and convenience in operation. Used for welding pipes with the smallest diameter.

External equipment, in turn, can be divided into subspecies, depending on the method of fastening the joints and the size of the pipes in diameter:

• chain design - there is a chain available, thanks to which the segment for welding is attached and fixed;
• link - is a set of links, due to which the pipe is regulated and moved for a more comfortable position;
• eccentric - consists of a pair of arcs of metal, pulled together by a jumper.

Additional types of pipeline centralizers include a mobile household device with a small diameter, as well as external equipment with a spring casing.

How to choose a unit?

The selection of a centralizer for welding a pipeline is one of the most difficult tasks in order to properly equip water supply, sewerage or other public utilities. This design makes it possible to smoothly connect one pipe to another at the correct angle of inclination, so that the seam will be reliable and durable.

Welding drawing using a centralizer.

There are two main features in this selection:

1. It is necessary to determine the cross section of the pipes.
   It is important to choose the right size for pipes with a large diameter, since it must be the same size as the other pipe to be welded. For work with a small diameter, you will need open equipment, for a large one, it is better to choose a closed unit. The latter method is more difficult to manage, but securely fixes the elements.
2. When choosing between chain, link or eccentric equipment, you must be guided by your finances and the planned amount of operation.
   The first option is quite cheap, multifunctional, but not reliable. The second is the golden mean of the units under consideration. The most expensive and high-quality are eccentric devices. Their peculiarity lies in the fact that they are lightweight on the outside, which allows you to quickly and better cope with the task.

Outcome

Based on the foregoing, we can conclude that the use of internal centralizers for pipe welding makes the process organized and of high quality, which is important for such a field of activity as construction.

Thanks to the correct choice of this product and the application of all recommendations, the result will be durable and reliable, which will increase the effective operation of the pipeline over time.

The most important stage in the installation of the pipeline is the welding of individual pipe fragments into a single whole. This work is carried out using special devices that allow you to perfectly position them relative to each other - pipe centralizers.

What does it consist of and how does it work?

The device is a mechanism that consists of thrust elements and devices that keep the pipes stationary during welding. An exemplary diagram of the device is shown in the figure.

The benefits of using are as follows:

• allow pipes to be welded precisely, which reduces the risk of their rupture and ensures a long service life of the pipeline;
• these are mobile mechanisms that can be easily carried for pipe welding in different places;
• they are mostly affordable;
• they are multifunctional, since they allow you to work with different types of pipes (steel, polyurethane foam, etc.);
• they connect pipes of almost any diameter. In particular, they are needed for the installation of main pipelines for transporting water, oil or gas. Even small deviations in these systems are fraught with serious consequences.

Models and prices

An overview of prices for some models is presented in the table below.

The price difference is due to several reasons:

• Purpose of the device- professional is much more expensive than domestic.
• Design features(presence or absence of hydraulic drive).
• Manufacturer's brand.

IT IS INTERESTING. For domestic purposes, it is quite possible to make a pipe centralizer with your own hands. For him, you will need improvised means and tools that are easy to get. In addition, this option will cost much less than the purchased one.

Kinds

The division by species is based on various characteristics:

1. according to the peculiarities of the location of the centralizers relative to the pipes being welded - internal and external;
2. according to the method of fastening on the pipe during its welding - chain, eccentric, arched type, pipe and link (multi-link);
3. Finally, according to the areas of application, centralizers can be conditionally divided into domestic and professional. In the first case, they often work in manual mode, are small in size and are used in laying home plumbing (for example, in the country). In the second, we are talking about complex, expensive mechanisms that ensure the laying of main pipelines of any diameter and in almost any climatic conditions.

External and internal

Devices can be used for welding pipes of almost any diameter. If the dimensions are small (usually from 20 to 2000 mm), then the device is mounted around the pipe, and then we are talking about an external centralizer.

External centralizer

In fact, this is a pipe clamp that wraps around their surfaces and provides a fixed position during installation and welding work.

An example of using this equipment in operation can be found here.

External centralizers for pipe welding in comparison with internal ones have their undeniable advantages:

1. they are light and have small dimensions, so they can be easily moved to any place;
2. allow you to work in all weather conditions (from -60 to +60 degrees Celsius);
3. provide high-quality welding of not only 2 pipes, but also entire water pipes;
4. mounted on pipes and dismantled from them easily and quickly.

The only significant drawback of such a device is that welding work has to be carried out with short interruptions - first the seam is made on a free surface, then the device moves and a new shock is made, and so on.

Internal centralizer

If it is required to weld pipes of large diameters (usually more than 2000 mm), then internal pipe centralizers are used in the work, which are not mounted on top of them, but are placed directly inside, firmly resting against the surface.

The location of the internal pipe centralizer is as follows.

Since such equipment is intended for the installation of wide pipelines, its dimensions are also very large. Accordingly, the internal device can be transported only by transport.

However, they also have their own indisputable advantage in comparison with the external ones - since they are installed inside the pipe, welding can be carried out continuously.

Installation work is always carried out using additional lifting equipment, as shown in the video.

The standard set of equipment is represented by the following elements:

• barbell;
• clamps for pipes;
• cable;
• manometer for pressure control;
• electric drive pump;
• lights.

NOTE. For welding, an influx of fresh air is required, which cools the internal surfaces, thereby preventing them from severe overheating. Special fans help to ensure this process. Usually they are not included in the basic delivery option, they are ordered additionally at the request of the buyer.

IT IS INTERESTING. Internal centralizers for welding work are not always used in the work of pipes of large diameters. They are also effective in the installation of small (up to 500 mm in diameter) pipes, as they ensure their precise installation with each other. The stop in this case is achieved not due to hydraulics, but due to conventional springs, as shown in the figure below. The drive in this case works manually by turning the handle.

The principle of operation of the mechanism is based on a hydraulic jack (shown in small and close-ups in the figure), which is driven by electricity, which is why it is often called an electro-hydraulic pipe centralizer.

This device performs two important functions:

• Provides maximum stop to prevent pipe vibrations during welding.
• Eliminates the deflection of the installed pipe, which can occur as a result of subsidence of the soil or due to the severity of the pipe itself.

The most important technical characteristic of the device is the diameter of the pipes to be centered, on which the mass of the centralizer itself also depends. These data are shown in the table below.

Device drawings

Centralizers according to the method of mounting on the pipe

External centralizers for pipe welding can be attached to the pipe in different ways. Accordingly, the following types are distinguished:

Video instructions for using the clamp clamp

Pipe mounting procedure

The principle of mounting the centralizer is fundamentally independent of the specific type and model of the device. However, there are some features of the internal and external. They are connected with the preparation of the pipe for welding.

Installation of the internal centralizer

To correctly mount the internal type device to the pipes to be welded, the following steps should be performed:

• First of all, it is necessary to carry out preparatory work - the joints of the pipes to be welded must be well cleaned of paint, clogs, rust and other foreign matter. This is done with the help of tools or special chemicals. In 1 case, the most popular grinder, which is planted with a metal brush.

You can also use a regular grinder.

Video example of stripping a pipe before welding.

In the case of old, difficult to remove paint stains, you can also use a building hair dryer - under the influence of hot air currents, the paint begins to soften, after which it can be easily removed with ordinary emery.

At home, you can use sandpaper to clean it or use household chemicals - for example, you can dissolve the paint with acetone, and then wipe the pipe dry with a clean rag.

IMPORTANT. Work with acetone should be done only outdoors in moderately warm weather and away from sources of open fire, since the substance is toxic and flammable (+40 C is enough).

• After carrying out a complete cleaning of the joints, it is necessary to fix the internal centralizer on the edge of one of them.
• The other pipe is pushed tightly to the first one, after which the limit stop is created using a spring mechanism (manual feed) or hydraulic drives.
• Make sure that the connection is made correctly and proceed with welding.

Installation of an external centralizer

The installation of this device is fundamentally different in that it is fixed on the outer surface of the pipe. Accordingly, the sequence of actions will be somewhat different:

• At the beginning, the joints are also cleaned, as described above.
• Then 2 segments are brought to each other, and the centralizer is put on over them at the junction.
• The connecting bolts are inserted into special holes and tightened tightly.
• Finally, the reliability of the installation is checked. and welding begins.

Video installation instruction

Specifications

When choosing a specific model of centralizer for pipe welding, several parameters must be taken into account:

• Pipe diameter - internal more often for large, external - for small (up to 900 mm).
• Pipe material - for example, if they are covered with polyurethane foam (the so-called PPU pipes), then they can only be welded using an internal device.
• Scope of work - if we are talking about laying a small private water supply (for example, in a country house), then a chain model is enough, which is the most affordable. If we are talking about professional work, then it is better to choose among link and eccentric models. The latter are the most expensive, but at the same time they are more reliable and last longer.
• The pressure of the contents of the pipes on the inner surfaces - if it is more than 5 atmospheres, then a device with a hydraulic clamp will be required for the installation of such pipelines.

NOTE. The main factor influencing the choice is the pipe parameters (material, diameter, strength). This is what should be taken into account when buying a centralizer.

Video example of assembling a centralizer with your own hands

Other devices for fixing pipes during their welding

Along with centralizers, which are often used in a professional environment, there are several other devices that allow you to securely fix joints during welding. The main purpose of these devices is to maintain the pipe in the desired position by creating an emphasis on a solid surface. They are divided into several varieties:

A separate class of pipe fixation devices are chain vise. The basis of the mechanism is a chain, which is made of especially durable varieties of alloy steel. A characteristic feature of the device is the ability to work with pipes of any diameter due to a simple adjustment mechanism - chain lengthening or shortening.

They are classified into several groups depending on the work performed:

Finally, a whole class of multi-row vices is distinguished, which are used in special cases, for example, when drilling wells. They can replace several conventional vices. The design of the chain is designed in such a way that the vise does not get stuck even under maximum load. So that the surface of the pipe does not receive severe damage from the pressure of the chain, it is supplied with steel liners that can be replaced as they wear.

Chain vise is a fairly popular option for a pipe centralizer, as it has obvious advantages:

• They are simple and easy to use even among amateurs.
• They serve for a long time and practically do not need maintenance, except for periodic lubrication of the working surface of the chains.
• Quite affordable (below is a comparison table with an overview of some models).

A brief video overview of the different types of vise from one of the well-known manufacturers RIDGID can be seen here.

Vice at home: do it yourself

Of course, in extreme cases, you can get by with homemade devices for fixing pipes. Here are some of them:

However, using artisanal production methods, safety precautions must be taken into account:

• First of all, you need to understand that welding is a source of elevated temperature, which means that all structural elements should not be made of flammable materials - for example, wood.
• The main requirement for the pipe centralizer is the rigidity of the fastening and the reliability of the design. It is worth remembering that during the implementation of welding work, the pipe will inevitably sway, therefore, a home-made system must initially be very strong.
• All handicraft tools are suitable only for small pipes, mainly for making straight joints between them. If you have to work with large, heavy pipes or perform complex joints, then such tools will definitely not work.

Consequences of incorrect welding

In the case of an incorrect choice of the centralizer or non-compliance with the rules for working with it, a whole range of consequences can occur, which are called welding defects. These include:

• cracks;
• pores, small cavities;
• lack of penetration as a result of incomplete coverage of the metal surface by welding machines;
• various deviations of the structure of the seam - excessive bulge, offsets, undercuts and others.

All these defects will inevitably lead to the fact that the pipe will not last long. The consequences are exacerbated by the nature of operation and external factors:

• pressure drop of internal contents (water, oil, gas, etc.);
• temperature difference (internal and external);
• the effect of corrosion.

Penetrating into microcracks, water and air significantly accelerate the processes of metal decomposition (corrosion). This will lead to the fact that the pipe will soon leak, the pressure in the system will drop, and accordingly, a breakthrough may occur. Therefore, a competent choice of pipe centralizer and its correct operation at all stages of welding work is an essential condition for the installation of pipelines of all types.

During the construction of both residential and industrial buildings, a welded connection of pipe communications is always made, but it cannot be carried out at the proper level without such a device as an external centralizer for pipes.

It is he who helps to avoid a number of inevitable welding defects:

• cavities

• cracking

• lack of fusion

• undercuts

• influxes

These defects very quickly disable the main pipeline. Which in turn leads not only to losses, but also injuries to the staff. After all, such substances as water, gas, oil, sewage are pumped through pipelines. All of them are quite aggressive, prone to jumps in internal pressure and temperature.

Even if unevenly welded pipes withstand the beginning of operation, then after a short time, microcracks in the seams quickly corrode, the strength of the metal drops and a breakthrough follows. All this can be avoided only by using an external centralizer for pipes in accordance with the rules for its use and, without exception, for all connections on the highway.

What does it consist of and how does it work?

At its core, the centralizer is a device that connects the welded joints of two pipes in a perfectly even position. The design allows to use it for work with pipes of various sizes. It is easy and quick to mount and weighs relatively little.

The external centralizer for pipes of any type consists of a connecting device (plates, clamps or chains) and a tightening part (screw collar, bolted connection, hydraulic drive).

To connect two pipes follow a simple algorithm:

1. Clean their joints with an angle grinder, clean rust and other contaminants with appropriate chemicals (rust neutralizer, acetone, white spirit, etc.)
2. They put the centralizer on one of the pipes, but do not tighten its fasteners.
3. Bring the second to the joint to the first.
4. Move the centering device to the second and tighten the fasteners with a uniform force
5. A visual check is made of the correct position of the pipeline and the reliability of the centering device.
6. Seams are applied using gas or electric welding.

As the seam is applied, the centering device must be carefully loosened and rotated - freeing up the working area for welding. During this procedure, you need to be especially careful, as it is easy to deform the unfinished weld.

Models and prices

All centering devices available on the market for tools and fixtures are divided by price into two groups:

1. domestic production. They are distinguished by a fairly reasonable price and ease of repair.
2. Foreign production. They are distinguished by great ease of use, ergonomics, but have a significant drawback - a high price. Among the manufacturers, it is worth highlighting the EU and the USA - their equipment is of consistently high quality, but also consistently expensive. The price is somewhat lower for products manufactured in Asian countries (with the exception of Japan - the cost of their products may exceed the price of EU products), but there is no guarantee of quality. It can vary greatly from the same manufacturer, even within the same batch.

The price of an external centering device fluctuates around 3-5 thousand rubles per piece (with a manual drive), if the external centralizer for pipes is equipped with a hydraulic drive and often with an electric pump to it, the price increases 6-10 times and is about 100-150 thousand.

The cost of internal centering devices, regardless of the manufacturer, does not fall below 250-300 thousand. The presence of hydraulics in their design increases the cost by 35-40%.

Types of centralizers

Centralizers are divided into two types:

• outdoor

• internal

Each of them has both positive and negative sides. Internal ones are always more expensive - they are almost ten times more expensive than external ones.

Centering devices are divided into types according to several criteria:

1. The volume of work carried out - if it is significant, then the purchase and use of a professional device is justified, if not, then a semi-professional one. The prices for these two types of centralizers differ by an order of magnitude.
2. At the location of the centralizer - on the surface of the pipes or inside them.
3. According to the fixing mechanism - a chain, an eccentric, a clamp, an arch.

External and internal centralizers

It is technologically and economically expedient to use external centralizers for pipe welding when working with pipe joints with a diameter not exceeding two meters. If the diameter is larger, it is recommended to use internal centralizers. But exceptions are possible - some designs of internal centralizers can be effectively used when working with pipes with a diameter of half a meter. But such work should be massive - then the cost of the device will be justified by the result.

External centralizer

The external pipe centralizer can be used for both amateur and professional purposes. The range of diameters it works with extends from 2 cm to 2 meters . On the video given in the article, you can get acquainted in detail with all the nuances of working with this type of centralizer.

Internal centralizer

This type of centralizer is effective when working with large pipe diameters ( from 2 meters). Its main advantage is the possibility of continuous work of the welder and a guarantee against deflection of the pipe walls.

Structurally, the internal centralizer is a movable hydraulic jack with an electric drive. With the help of semi-cylinder spacers, it fixes both pipes from the inside. In addition, it can (some expensive models) also carry out internal air cooling of the superimposed welded joint.

You can also see the details of working with the internal pipe centralizer in the attached video.

Device drawings

Here are the basic drawings of the most common external centering devices in industrial practice.

Centralizers according to the method of mounting on the pipe

According to the method of mounting on the pipe, all external centering devices are divided into five types:

1. Clamp- very convenient for connecting relatively small diameter pipes. Often used by hobby craftsmen and small businesses. Their main part - the capture can be performed in a form suitable for a particular pipe (trapezium, circle or parallelepiped). Its lower part is an additional support during installation. Easy to repair, reliable, low cost. Are simple in operation.
2. Eccentric- by design, they actually coincide with arched ones, but they have a significant addition - an eccentric. It is a lever that pulls together the two working halves of the device. The use of an eccentric speeds up centering, but requires considerable experience. In case of an error with the force and place of installation of the device, it may suddenly open at the time of pipe welding. The cost is slightly higher than the arched version.
3. Chain- the main part of this device is a kind of chain, tightened on the pipes by a special mechanism. Due to the low-power gearbox, the mounting process is rather laborious, but such a mechanism is reliable and cheap.
4. Arched- simple devices of two fastening elements. The action is often driven by a hydraulic drive (with the help of human muscle power). Most often they are used when connecting pipes with a diameter of up to 1 meter.
5. Multilink- Structurally, they are a transitional option between arched and chain ones. They can have both a manual drive (screw gate) and a hydraulic drive. Highly efficient when working with pipes with a diameter from 1 to 2 meters.

Any of them can be equipped with a hydraulic drive and an electric pump to it.

• If the scope of the proposed work is small, then it is more profitable to make an external centralizer on your own. It does not require rare materials and special skills. All you need is a regular locksmith shop.
• Whatever type of centralizer is used - external or internal, but it is always necessary to carry out air cooling of the welded pipes from the inside. This is done by special fan installations. They are not included in the scope of delivery of centralizers.

Welding the joints of a metal or PPU pipeline is a very responsible task. It is from the quality of the welds and the correct slope at the level of the water supply, sewerage or heating mains that their service life will depend.

The most difficult thing in the pipe welding process is to center the joints before starting welding. This is especially true for large diameter products. Automatic pipe centralizers will help to cope with this task without wasting time and effort.

Article content

What is a centralizer?

Every welder knows that reliable fastening of the elements to be welded is the key to a good result. If pipes prepared for welding are not centered and securely fastened, they may vibrate and oscillate during operation. This will lead to the seam will come out voluminous, weak and unreliable. At the slightest load, it can leak, or even burst.

Such negligence is unacceptable even when installing household pipelines of small diameter with little pressure and no external load. As for industrial, especially underground, highways, such irresponsibility can be very expensive in the future.

That is why in the process of welding segments, especially large diameters, pipe centralizers or guides are always used.

Their task is to securely fix the joint of the pipeline to ensure a high-quality weld.

The centralizers consist of the body of the device (tensioning mechanism), a stand or a hook and individual typesetting elements, changing the number of which allows you to connect lines of different, including small, diameters.

This equipment is fixed around the joint of two pipes prepared for welding and tightly attracted using a tensioning mechanism.

The centralizer can be both external and internal. Internal centralizers are used mainly for fixing PPU pipes, or in cases where the working space does not allow the use of an external mechanism.

In other cases, an external one is used. This is due to the fact that the internal guide is more expensive and much more difficult to install.

We also note that the centralizer for welding polyurethane foam pipes of large diameter - The device is quite bulky and heavy. Therefore, its use requires the use of additional equipment.

The process of welding plastic pipes using a centralizer (video)

Pros and cons

Like any device, tubular centralizers have their advantages and disadvantages.

We refer to the advantages:

• wide functionality. It is not required to purchase guides separately for each diameter;
• the ability to work with both metal and PPU pipes;
• high-quality and reliable fixation of the connected elements;
• the presence of two modifications - internal and external, which allows you to fix the segments in any conditions and workspaces;
• ensuring high-quality welds, which are the key to the reliability of the pipeline.

The disadvantages of this equipment are associated primarily with its bulkiness.

• quite high price. However, we note that if you are constantly welding pipelines, centralizers will pay for themselves in a short time;
• design complexity. Working with this equipment requires certain knowledge and skills;
• bulky and heavy weight (when it comes to welding steel pipes and large-diameter polyurethane foam);
• when connecting segments of large diameter, the use of special equipment is required.

Although pipe centralizers have a number of disadvantages, there is nothing more reliable for welding pipelines, especially for industrial purposes. This device will pay for itself with interest thanks to the installation of reliable pipelines, that will last for years.

Types of centralizers

There are two ways to divide pipe centralizers into subspecies. They are subdivided based on the area of ​​fixation and the method of fixing.

According to the fixation area, the guide mechanism for PPU or metal pipes can be internal and external.

1. Internal devices are installed inside the connected segments to fix the PPU pipes or from any other materials in the correct position. This equipment is used, as a rule, on large diameter pipelines. It has a rather complex design and provides for the presence of hydraulic pumps, an engine and locking mechanisms.
2. The outer centralizer wraps around the welded joint from the outside. It is a rather massive clip of a universal design. It is simpler and more convenient to use.

If the internal mechanisms can only work due to hydraulic pumps, then the external ones can be divided into several more categories according to the method of fastening at the joints of PPU pipes or any other products of large and small diameters.

• chain. Around the joint, with the help of special tension chains, a chain is fixed, which fixes the segments for welding;
• link. This device consists of a set of links that can be moved and adjusted based on the diameter of the pipe;
• eccentric. Such centralizers consist of two metal arcs, which are pulled together by a jumper.

In addition to the main, most commonly used guides, there are several less popular devices:

• outer centralizer spring casing. It is used, as a rule, in vertical drilling, to connect PPU. Such equipment has the form of a metal pipe cut around the perimeter with a bulge at the cut points. It is this bulge that gives the equipment its springy effect;
• mobile household devices for connecting PPU pipes of small diameter.

Unit installation

Installation of external centralizers is somewhat different from internal ones. It is performed more simply and quickly.

How to mount the indoor unit:

1. We clean the joints to be joined.
2. We fix the unit in one of the elements.
3. We fix the spring centralizer near the edge of one of the segments.
4. We install the second element close to the first.
5. We start the engine. Hydraulic pumps compress the segments, leveling them out due to the inner diameter.
6. We weld the joint.

Outdoor unit installation procedure:

1. We prepare the joints.
2. We install the unit.
3. Align the segments according to the level.
4. We tighten the bolts of the centralizer.
5. We check the correctness of the connection.
6. We clamp the tension to the stop.
7. Let's start welding.

How to choose a centralizer?

The choice of a centralizer for pipe welding is perhaps one of the main tasks in the arrangement of a water supply system, sewerage or heat pipeline.

It is this equipment that will allow hermetically connecting pipes and maintaining the correct slope angle, which is the key to the reliability and durability of any pipeline. The nuances are:

1. Decide what section of pipes you will have to deal with. For work with elements of small diameter (up to 500 mm), an open unit is quite suitable. To connect products from 500 mm, it is better to use a closed device. It is more difficult to manage, but provides a more secure fit.
2. To choose between chain, link and eccentric models - decide on the amount of work and the thickness of your wallet. Chain models are the cheapest, most functional, but least reliable. The link devices are average in all parameters. The most expensive, but most reliable - eccentric centralizers. However, for domestic pipelines, throwing out $150-200 for auxiliary equipment is at least not rational.