home » Marketing » Bellows expansion joints of the Hydra brand, information on types ARN, ARF. Sale of HYDRA ARN and ARF bellows expansion joints (with protective casing and screen)

Bellows expansion joints of the Hydra brand, information on types ARN, ARF. Sale of HYDRA ARN and ARF bellows expansion joints (with protective casing and screen)

Compensators HYDRA- these are products High Quality from the German manufacturer Witzenmann.

Application

The HYDRA bellows expansion joint is designed to compensate for pipeline contractions and expansions in heating systems and hot water supply systems. In addition, the HYDRA axial expansion joint can be used in systems with liquid media that are not aggressive towards the construction material.

HYDRA expansion joints are manufactured from bellows made of of stainless steel and branch pipes, which are made of carbon steel. These structures are used in main pipelines, on risers in multi-storey buildings.

Today, the most popular is the HYDRA bellows expansion joint of the ARF or ARN type. The design is a stainless steel bellows and steel pipes. The HYDRA ARF bellows expansion joint is equipped with an inner screen to protect against mechanical particles in the working environment and an outer casing that protects against external damage.

Specifications:

Du - 10, 16 MPa, Di - Risp 13 or 20 MPa;
working environment - water, steam and gas;
connection - welding;
manufacturer - Witzenmann.

Axial expansion joint HYDRA - types:

ARF - with outer casing;
ARN - without outer casing;

Components and materials:

bellows (corrugation) - stainless steel 316Т1 or 316L;
butt-weld pipes - St 35.8;
inner sleeve - stainless steel;
protective casing - stainless steel.

HYDRA bellows expansion joint - selection

The HYDRA bellows expansion joint type ARF or ARN is selected according to the diameter of the pipeline. The number or distance between the supports is determined by the compensating capacity, as well as the calculated elongation of the pipeline. The expansion capacity is usually equal to half the axial elongation if the expansion joint is not stretched during installation or in the factory.

The elongation value of the pipeline is found using the formula for temperature linear elongation. The average coefficient of thermal expansion for the HYDRA ARF and ARN expansion joints is:

carbon steel - o = 0.01-0.012 mm / (m "K);

stainless steel, copper - o = 0.0145-0.0155 mm / (m "K).

So, in heating systems with a temperature variation of 0-90 0 The extension of pipes made of stainless steel is 1 mm per meter of pipeline. For vertical risers of a traditional heating system, fixed supports are installed at intervals of 20-30 meters. In this case, the compensator is located between the fixed supports in such a way that the displacement of the pipes on each side of the compensator is not more than 10-15 mm.

When calculating the forces of a fixed support, it is taken into account that at a pressure of more than 50 mm, it can be quite large. One of the components of the force is determined by half the amount of compression times the stiffness. But the main component of the effort is still high pressure in the pipeline and in the bellows. It is determined by the maximum working and test pressure by the formula: F = AxPx 10. F is the force on the support in Newtons, P is the maximum pressure in bar, A is the effective area in sq. cm.

Using the HYDRA ARN bellows expansion joint

To allow compression, the outer and inner parts of the bellows are protected from mechanical stress and pollution. Thus, ARN10.xxxx.xxx.O does not include an inner sleeve and provides complete cleanliness, free from contamination and solid particles in the form of sand, deposits or scale. If the pipeline is laid in residential premises, an outer casing is installed for optimal protection from external factors, while its inner diameter is larger than the outer diameter of the corrugation.

In a vertical riser, the casing is closed at the top with a snug fit to the pipe. That is, it can be additionally insulated. It is prohibited to insulate HYDRA ARN expansion joints without an outer casing. In axial expansion joints, there is no resistance to twisting loads, so they should not be present during installation or operation. The test pressure should not exceed the nominal 1.3 times.

Mounting HYDRA ARN

This model does not have an outer casing and a pretensioner. When using HYDRA ARN in heating systems with pipe extension, certain steps must be taken during installation. The compensator is pre-stretched by 50-70% of? compensating ability.

Thus, ARN16.0025.040.1 with a diameter of 25 mm and an initial length of 220 mm has a compensating capacity of 40 ± 20 mm. Stretching can be done up to 10-14 mm. On average, this is 12 mm. The calculated compression resource will be determined at 10 thousand cycles. The ultimate compensating capacity is 32 mm (12 + 20).

And even if the expansion joint has internal guide sleeves, it is still necessary to install sliding supports next to the expansion joint. The optimal distance in this case is 3xDu. In vertical risers, the casing in the ceiling can become a support.

Work rules:

fix fixed supports;
at the design points of the pipe, certain sections are cut out that correspond to the calculated length. In this case, the preliminary stretching is taken into account. The pipeline cannot be started if the length of the tie-in is less than the nominal length of the expansion joints;
expansion joints are checked for compression and expansion within the limits of the compensating capacity;
one side of the expansion joint is welded to the pipeline, then it is stretched to the full length of the cut-out section, and then the other end is butt-welded by spot welding. The bellows must not be exposed to welding sparks and welding current;
if the inner sleeve and ARN are not symmetrical, then the fluid inlet must be with a short butt weld stub.

HYDRA bellows expansion joint type ARF - use

The HYDRA ARF bellows expansion joint must be thermally insulated. It is not resistant to torsional loads and should therefore be avoided when installing and operating the structure. The test pressure should not exceed the nominal 1.3 times.

Axial expansion joint HYDRA ARF - installation and operation

The expansion joints are equipped with an internal guide sleeve, a protective cover and a pre-stretch lock. That is, the structure is supplied from the factory with a preliminary tension, which is fixed with a temporary retaining half-ring made of wire. Fits between inner and outer chuck.

According to the instructions, in addition to lateral deformations, it is necessary to install sliding guide supports (sometimes sliding and fixed). The optimal distance in this case is 3xDu. In vertical risers, the casing in the ceiling can become a support.

HYDRA bellows expansion joint - installation:

drive a solid riser and install fixed and guide supports;
fix the fixed supports on the pipe;
at the design points of the pipe, certain sections are cut out, which correspond to the calculated length of the compensator with a retainer. In this case, the preliminary stretching is taken into account. The pipeline cannot be started if the length of the tie-in is less than the nominal length of the expansion joints;
check the HYDRA bellows expansion joint for mechanical damage to the bellows;
insert the compensator into the cut-out section, while the arrow of the compensator must correspond to the direction of the coolant;
the ends of the expansion joint are welded to the pipe;
remove the stretch retainer.

The bellows must not be exposed to sparks and welding current during welding.

It is also worth noting that the price of HYDRA for a bellows expansion joint is quite affordable, given the service life, reliability and practicality of this design.

Type: axial bellows expansion joint with outer protective casing and inner protective sleeve.

Axial stainless steel ARF bellows expansion joints with carbon steel tubing.

Axial expansion joints of the ARF type are designed to compensate for temperature elongations of pipelines of heating and hot water supply systems, as well as in industrial systems for liquid media that are not aggressive to the construction materials of the expansion joints.

These expansion joints are intended for installation on risers and main pipelines of heating systems in multi-storey buildings. Axial expansion joints ARF consist of a bellows (corrugated cylinder) made of stainless steel and welded carbon steel pipes.

Axial expansion joints can be equipped with an inner sleeve and an outer casing for additional protection of the bellows.

The main specifications expansion joints ARF

Nominal and maximum working pressure: PN 10 bar (PN test 13).

Working medium: water, steam.

Working environment temperature: Т = -10 ... 300 ° С.

Connection to the pipeline: for welding.

Manufacturer: Witzenmann (Germany).

Axial expansion joints HYDRA ARF PN 10 bar with inner sleeve and outer protective cover

Nominal bore DN, mm	Code number	Nominal axial elongation 2δ, mm	Nominal pressure PN and maximum working pressure Pp, bar	Maximum temperature of the transported medium T max., О С
15	ARF 10.0015.032.2	32 (± 16)	10	300
15	ARF 10.0015.064.2	64 (± 32)
20	ARF 10.0020.040.2	40 (± 20)
20	ARF 10.0020.080.2	80 (± 40)
25	ARF 10.025.036.2	36 (± 18)
25	ARF 10.025.064.2	64 (± 32)
32	ARF 10.0032.036.2	36 (± 18)
32	ARF 10.0032.080.2	80 (± 40)
40	ARF 10.0040.036.2	36 (± 18)
40	ARF 10.0040.064.2	64 (± 32)
50	ARF 10.0050.048.2	48 (± 24)
50	ARF 10.0050.080.2	80 (± 40)
65	ARF 10.0065.040.2	40 (± 20)
65	ARF 10.0065.080.2	80 (± 40)
80	ARF 10.0080.040.2	40 (± 20)
80	ARF 10.0080.080.2	80 (± 40)
100	ARF 10.0100.048.2	48 (± 24)
100	ARF 10.0100.080.2	80 (± 40)

Nomenclature and code numbers for ordering ARF expansion joints

The main parameters and characteristics of the compensator can be determined by the code number in accordance with the example below.

Basic elements and materials of ARF expansion joints:

316Ti or 316L stainless steel bellows (corrugated cylinder); butt-weld pipes made of carbon steel St 35.8 (GOST 10); inner sleeve made of stainless steel; outer casing made of stainless steel.

Overall and connecting dimensions of ARF compensators, technical characteristics for calculating the forces on the fixed supports of the pipeline

Du - nominal bore, mm; 2δ - nominal axial elongation, mm; L0 - full length of the compensator in a free state, mm; d is the outer diameter of the branch pipe, mm; s is the wall thickness of the branch pipe, mm; D is the outer diameter of the bellows, mm; I is the working length of the bellows, mm; A - effective area, cm2; C - axial force (stiffness), N x mm.

Compensator brand	DN	2δ	L0	d	s	D	I	Weight G, kg	A, cm 2	C, N / mm
ARF 10.0015.032.2	15	± 16 = 32	200	21,3	2,0	28,0	90	0,37	4,4	28
ARF 10.0015.064.2	15	± 32 = 64	312	21,3	2,0	28,0	170	0,53	4,4	11
ARF 10.0020.040.2	20	± 20 = 40	226	26,9	2,3	36,5	116	0,62	7,6	30
ARF 10.0020.080.2	20	± 40 = 80	354	26,9	2,3	36,5	212	0,94	7,6	16
ARF 10.0025.036.2	25	± 18 = 36	216	33,7	2,6	43,0	106	0,75	10,7	39
ARF 10.0025.064.2	25	± 32 = 64	332	33,7	2,6	43,0	190	1,10	10,7	21
ARF 10.0032.036.2	32	± 18 = 36	238	42,4	2,6	56,0	118	1,20	18,2	39
ARF 10.0032.080.2	32	± 40 = 80	362	42,4	2,6	56,0	210	1,80	18,2	23
ARF 10.0040.036.2	40	± 18 = 36	238	48,3	2,9	60,0	118	1,30	21,3	55
ARF 10.0040.064.2	40	± 32 = 64	324	48,3	2,9	60,0	172	1,90	21,3	38
ARF 10.0050.048.2	50	± 24 = 48	214	60,3	2,9	77,0	94	1,40	35,6	32
ARF 10.0050.080.2	50	± 40 = 80	356	60,3	2,9	77,0	186	2,70	35,6	26
ARF 10.0065.040.2	65	± 20 = 40	216	76,1	3,2	95,0	96	2,30	53,0	37
ARF 10.0065.080.2	65	± 40 = 80	420	76,1	3,2	92,0	250	4,50	53,0	33
ARF 10.0080.040.2	80	± 20 = 40	214	88,9	3,2	106,0	94	2,60	73,2	47
ARF 10.0080.080.2	80	± 40 = 80	384	88,9	3,2	106,0	214	5,00	73,2	36
ARF 10.0100.048.2	100	± 24 = 48	214	114,3	3,6	130,0	94	3,30	115,0	73
ARF 10.0100.080.2	100	± 40 = 80	356	114,3	3,6	130,0	186	5,80	115,0	56

Selection of HYDRA expansion joints

HYDRA ARN and ARF expansion joints are selected according to the pipe diameter on which they are installed. Their number (or the distance between the fixed supports) is determined depending on the calculated elongation of the pipeline and the compensating capacity, which, as a rule, is taken equal to half of the nominal axial elongation of the compensator, if the compensator is not pre-stretched during installation or at the factory (the latter is the case for the type ARF).

The amount of pipeline elongation under the influence of the coolant temperature can be found using the formula for the temperature linear elongation of the metal:, mm,

where L is the length of the pipeline section, the elongation of which is required to be compensated, m;

Average coefficient of thermal elongation, mm / (m.K);

Temperature difference between working temperature pipeline and temperature environment when installing the pipeline, K.

Average coefficient of thermal expansion of HYDRA ARN and ARF expansion joints

carbon steel: α = 0.01-0.012 mm / (m.K), and for stainless steel and copper: α = 0.0145-0.0155 mm / (m.K).

Thus, in heat supply systems, when the temperature changes from 0 to 90 ° C, the expected elongation of carbon steel pipes will be about 1 mm per running meter of the pipeline length. If we consider vertical risers of a traditional two-pipe heating system, then it is advisable to install fixed supports at least every 20-30 m (on the 6-10th floors of risers), placing the expansion joint approximately in the middle between the fixed supports so that the pipeline displacement on each side of the expansion joint and on adjacent floors did not exceed 10-15 mm, respectively.

When calculating the force on fixed supports, it should be borne in mind that with a steel pipeline DN of more than 50 mm, it can be a significant value. One of the components of the force on the fixed support is determined by the product of half of the compression value of the compensator by its stiffness C indicated in the tables. However, as a rule, the main component of the force occurs due to the high pressure in the pipeline and inside the flexible bellows. This component is determined by the maximum working or test pressure in the pipeline according to the formula:

F = A x P x 10; where F is the force on the support in N (in Newtons); P is the maximum (working or test) pressure in the pipeline in bar; A is the effective area of the compensator in cm2, the values of which are given in the tables.

Using the HYDRA ARF expansion joint

ARF expansion joints can be thermally insulated. Axial expansion joints are not resistant to torsional loads (rotation around the pipe axis). They should be strictly avoided both during installation and during operation.

The test pressure should not exceed the rated pressure by more than 1.3 times.

Installation and operation of axial expansion joints ARF in heat supply systems

The ARF is equipped with an inner guide sleeve, an outer protective cover and a pre-stretch lock. Thus, ARF is supplied from the factory with a pre-tensioned, which is fixed by installing a temporary retaining half-ring made of steel wire between the outer and inner sleeves of the protective cover.

The factory instructions indicate that even with an inner sleeve and an outer casing, as a rule, for additional protection against lateral deformations during operation, it is advisable to install guide sliding supports near the expansion joint (or sliding and fixed). It is recommended to install them at a distance of about 3 x DN from the expansion joint. For vertical risers, a sleeve in the ceiling can play the role of one of the supports.

Installation of ARF expansion joints (using the example of a vertical riser of a heat supply system)

(1) - drive a solid riser with the simultaneous installation of fixed and guide supports at the design points.

(2) - fix the fixed supports on the pipeline.

(3) - cut out riser sections at the design points of the pipeline in accordance with the actual length of the pre-stretched expansion joint with a retainer.

It is not allowed to start the pipeline if the length of the tie-in section is less than the nominal length of the ARF compensator in a free state (without a retainer, see length L0 in the table), i.e. when the compensator is installed in a pre-compressed state!

(4) - before installing ARF, it is necessary to visually check that there is no mechanical damage to the protective casing.

(5) - insert the expansion joint instead of the remote section of the pipeline so that the arrow on the expansion joint body coincides with the direction of the coolant flow, weld both ends of the expansion joint to the pipeline.

(6) - remove the pre-stretch clamp.

When welding, make sure that no sparks fall on the compensator (cover with non-conductive material) and that no welding current flows through it.

Operating instructions for HYDRA type ARF expansion joints

ARF expansion joints are maintenance-free.

The technical characteristics must fully comply with the conditions specified in the order.

The long service life of the expansion joints can only be guaranteed if they are correctly installed in the system, there is no damage and their mobility is limited.

General installation instructions.

Before starting installation, check the HYDRA expansion joint for possible damage.

Prevent damage to the bellows, protect it from impacts.

Do not attach chains and ropes to the bellows section.

Avoid splashing during welding, if necessary cover with insulating material.

Avoid a short circuit across the welding electrodes or cable - this could destroy the bellows.

Protect the corrugated part of the bellows from the inside and outside from the ingress of foreign substances (dirt, cement, insulating material) - check before and after installation.

Cover with a metal sheet before insulation with mineral wool.

Do not use insulating material containing corrosive components.

Avoid twisting during installation and operation.

Only remove the pre-tensioned yoke and the locking mechanisms after completion of installation, not before.

Provide sufficient dimensions of the support points of the pipeline section, they must withstand a very large axial load during pressure testing, as well as absorb the expansion joint's setting force and friction force. Axial compression force with axial pipeline compensation.

Pre-stress expansion joints and hinge systems after installation (except those prestressed at the factory) - usually 50% of the movement absorption - while monitoring the installation temperature and direction of movement.

Compensator Hydra ARF axial compression with axial pipeline compensation

Secure support points and guides before applying pressure.

Do not exceed the admissible test pressure! Installation instructions for HYDRA ARF axial and universal expansion joints.

There is only one axial expansion joint ARF between the two supports.

If several axial expansion joints are to be installed in a straight pipe section, they should be placed between light intermediate anchor points.

Pipelines with axial expansion joints must have guide supports. Axial expansion joints must have guide supports on both sides; Anchor points act as guide supports.

Intervals between pipeline guides with axial expansion joints.

Where the HYDRA ARF expansion joint is installed, the pipe ends must be aligned.

At the point of connection to vibrating equipment, the pipeline is fixed directly behind the expansion joint. Installation instructions for HYDRA anchored expansion joints.

If special hangers or supports are provided next to the compensation system, the lateral movements of the pipeline must be taken into account.

Provide correct position installation pivots: parallel to each other and vertical to the direction of travel.

When installing shear expansion joints, ensure that the tightening bolt is in a position that is appropriate for its function.

Bellows expansion joints under the brand name Hydra are manufactured by the company "Witzenmann GmbH", which is based in Germany. Official dealer German factory is. If you wish, you can buy suitable devices from this company.

Expansion joint information

Axial expansion joints HYDRA types ARN and ARF are designed to compensate for thermal expansion in pipelines of heating and hot water supply systems. These expansion joints are made taking into account that the working medium of the pipeline will be water, however, these devices are also used in industrial systems when transferring other non-aggressive liquid media.

If required, Hydra axial expansion joints can be equipped with an inner sleeve for additional protection of the corrugated part (bellows). the inner screen will protect the bellows itself from contact with water, and also neutralizes the possibility of turbulence in the flow when passing through the corrugated section of the pipe.

Axial expansion joints are completely made of stainless steel: bellows, branch pipes, inner screen. The use of stainless steel allows you to finally solve the problem of corrosion during the operation of expansion joints.

Hydra ARN bellows expansion joints have the following characteristics:

nominal diameter (DN) from 15 to 3000 mm;
nominal pressure (PN) from 2.5 bar to 40;
method of connection to the pipeline - welded branch pipes;
an inner sleeve is fitted if necessary.

Hydra ARF bellows expansion joints have a narrower range of parameters:

nominal diameter (DN) from 15 to 100 mm;
nominal pressure in the system 10 bar;
working temperature from -10 ° C to + 300 ° C degrees;
butt weld nipples for installation on the pipeline;
the product is completed with an inner screen (sleeve).

Axial HYDRA expansion joints of ARN and ARF types are certified by GOSSTANDART of Russia in the GOST R certification system. They also have a certificate of conformity, a license to use the conformity mark of the GOST R certification system and official letter TsGSEN that products are not subject to mandatory hygienic assessment.

Transportation and storage of HYDRA bellows expansion joints must be carried out in accordance with the requirements of GOST 22338-77. In this case, the manufacturer guarantees full compliance of Hydra expansion joints with the declared technical requirements... The classic warranty period indicated by the manufacturer is 1.5 years from the date of shipment. The expansion joints are packed properly at the factory, they are accompanied by a passport for the product, instructions for installation and operation.

Installation, commissioning, operation

During the installation of the bellows expansion joints, it is necessary to take measures to reduce the stress at the point where the bellows is attached. The bending moment must be distributed in such a way as to reduce the stress on the weld points. How can I do that:

raise the edge of the expansion joint, which will create a counter-torque that will reduce the load;
install mounting rings that strengthen the edge and reduce tension;
the cylindrical expansion joint reduces any residual stress.

The weld seam with which the expansion joint is welded is placed at a distance of about half the diameter of the expansion element, where the bending moment tends to zero, therefore, without exerting a destructive effect.

During welding, the safety measures in force at the facility should be adhered to. Technical specialists focus on the following points:

The fusion cable must not come into contact with the expansion joint bellows.
During welding, the expansion joint should be wrapped in a non-conductive material to prevent the ingress of metal particles. Pay special attention to the bellows.
It is not allowed to store bulk substances next to the expansion joints in order to avoid them getting into the bellows corrugations, and it is also not allowed to wrap the expansion joint bellows with chains and ropes.
Do not act on the torque compensator and do not subject it to strong shocks.

Bellows expansion joints are reliable and durable products. With a long range, they will keep your system running smoothly for years to come, without the need for maintenance.

Other advantages of HYDRA axial expansion joints include the following:

elimination of thermal expansion of the pipeline;
correction of some misalignment that appears after the installation of the entire system;
the fight against vibration that appears when the coolant moves;
creation of the necessary tightness on the pipeline;
long service life;
easy replacement after failure;
acceptable cost for a consumer of any level.

ARF bellows expansion joints are manufactured in Germany at the Witzenmann plant.

Description:

The HYDRA ARF bellows expansion joint has an internal protective screen that prevents damage to the bellows (corrugation) by mechanical particles of the working medium, as well as an external protective casing that saves the expansion joint from external harmful factors and damage. During manufacture, HYDRA type ARF bellows expansion joints are pre-stretched.

Material execution:

The bellows in this device is multilayer, it is made of stainless steel 1.4571 (AISI 316Ti) or 1.4541 (AISI 321), the inner screen and outer protective casing are made of stainless steel 1.4571 (AISI 316Ti) or 1.4541 (AISI 321). Weld ends are made of St35.8 steel.

The working medium in the pipeline can reach 40 ° C and this will not affect the trouble-free operation of the ARF compensator. Pressure for water - 1.0 or 1.6 MPa, for gas - 1.0 or 1.6 MPa.

Drawing:

The main parameters and characteristics of the compensator can be determined by the factory code. See example below:

Technical specifications:

Nominal diameter, mm	Nominal pressure, bar	Axial stroke, 2dN, mm	Length, mm