Contents Page Planning criteria 2 Criteria for a compressed air line 3 Air quantity 4 Operating pressure 5 Pressure loss 6 Configuration of a compressed air system 7 Selection of material and pipe system 11 Pipework design and installation 20 Dimensioning 27 Flange joints/screwed connections 32 Material 33 Storage 36 BEKOFLOW® HWSG-3 resistance welding tool 37 Symbols used in compressed air technology 41 The technical data are non-binding.
Compressed Air Applications Manual | Planning criteria Planning criteria for compressed air lines Criteria for the selection of materials Country-specific operating conditions Pressure and temperature specifications, lifetime, safety factors, fluid Environmental aspects Polybutene (PB) Criteria for dimensioning Required flow rate Required operating pressure Max.
Compressed Air Applications Manual | Criteria for a compressed air line Criteria for a compressed air line A compressed air line is an energy line designed to transport compressed atmospheric air with as little loss as possible from the compressor to the point of use.
Compressed Air Applications Manual | Air quantity Air quantity Compressed air should flow without loss from the compressor to the point of use. This means that the compressed air network has to be leakproof in order to avoid waste and unnecessary operating costs. The loss of air – i.e., of energy – through leaks in the distribution network or equipment results in a completely unnecessary increase in the operating costs. Hole diameter Ø Air loss in l/s at Compressed air is an expensive form of energy.
Compressed Air Applications Manual | Operating pressure Operating pressure Performance loss in % �� Every compressed air application (machine or tool) requires a specific operating pressure, in addition to the relevant air quality and volume. If the operating pressure is too low – for instance, 5 bar instead of 6 bar – the performance of the machine or tool will be reduced by some 30 %. An increase in the compression by 1 bar will result in additional costs of around 10 %.
Compressed Air Applications Manual | Pressure loss Pressure loss The economic performance of the compressed air system is of great importance for the plant operator. Increased flow resistance because of dimensioning errors (e.g., pipe diameter too small) or because of misguided saving on investment costs will result in a corresponding loss of pressure and thus push up the energy costs for the compressed air supply.
Compressed Air Applications Manual | Configuration of a compressed air system Configuration of a compressed air system Compressed air systems consist of three main elements: The distribution system is divided into: • • • • • • generation distribution, and consumption (points of use). the main pipe, distribution pipes, and connecting pipes.
Compressed Air Applications Manual | Configuration of a compressed air system Distribution The compressed air distribution network is divided into: • • • the main pipe (MP) distribution pipes (DP), and connecting pipes (CP) It is advisable to organize the pipe network according to function and use. The pipe joints should be continuity bonded in order to prevent leaks in the distribution system. Flange joints and screwed connections should preferably be avoided.
Compressed Air Applications Manual | Configuration of a compressed air system Main pipe (MP) The main pipe joins the compressor station to the distribution network. It should be dimensioned with adequate capacity for future expansion. The pressure loss in the main pipe should not exceed ∆p MP ≤ 0.03 bar. Distribution pipes (DP) The distribution pipes distribute the compressed air within a point-of-use section.
Compressed Air Applications Manual | Configuration of a compressed air system Connecting pipes (CP) The connecting pipe runs from the distribution pipe to the machine or compressed-air supply point. The way in which the connecting pipe is joined to the distribution pipe will depend on the actual air quality. If the air is not dried, the connecting pipe should be led to the top of the distribution line in order to keep out condensate. If the air is dried, the connecting pipe can lead directly downwards.
Compressed Air Applications Manual | Selection of material and pipe system Selection of material and pipe system Compressed air lines need to be tight, maintenance-free and adequately dimensioned. The materials for compressed air pipes can be divided into the two major groups: • • metals and plastics.
Compressed Air Applications Manual | Selection of material and pipe system Pressure/temperature limits and service life of polybutene pipes The following diagram shows the application limits of the material recommended by us. The service life of the PB systems was calculated to be 25 years, including a safety factor of 1.6. 20 permissible operating temp.
Compressed Air Applications Manual | Selection of material and pipe system Calculation of effective safety factor and permissible operating pressure For calculating the safety factor (SF) and the operating pressure (p), it is first necessary to know the endurance strength of the material. The endurance diagram for polybutene is set out on page 15. This diagram shows the relevant endurance strength value (comparative stress) as a function of the desired service life and the maximum operating temperature.
Compressed Air Applications Manual | Selection of material and pipe system Determination of pipe wall thickness and pressure class s = pipe wall thickness p = operating pressure at 20 °C δ B = comparative stress SF = safety factor The dimensioning of polybutene pipes under internal pressure is carried out strictly on the basis of the strength requirements using the compressed-air receiver formula: s = p x d x SF (20 x δ B) + (p x SF) The above formula is used for all the pipe dimensions laid down in the
Compressed Air Applications Manual | Selection of material and pipe system Endurance diagram of PB 4137 (see also DIN 16968/16969) The comparative stress indicates fracture stress δ B . 50 40 30 In other words, it shows the maximum load for the material in dependence on the temperature and service life. 20 20°C 60°C Comparative stress in N/mm² 10 9 Curves without safety factor.
Compressed Air Applications Manual | Selection of material and pipe system Safety The term “safety” covers a number of different aspects, such as: • • • • • fracture behaviour resistance against UV radiation and compressor oils corrosion behaviour in fire Since compressed air, contrary to water, is compressible (“squeezed” into a smaller space), mechanical damage to one of the pipes may result in an explosion-like expansion.
Compressed Air Applications Manual | Selection of material and pipe system Safety Equipotential bonding According to German standard VDE 0190, equipotential bonding is required between all types of protective conductor (PE) and existing “conductive” pipes. However, BEKOFLOW pipes are not electroconductive and can therefore not be used for equipotential bonding as stated in DIN VDE 0100.
Compressed Air Applications Manual | Selection of material and pipe system Depending on the pipe dimensions, the compressed air lines can be mounted using either pipe clips or cable binders. Since plastics are not electroconductive, pipe installation in the cable duct is a particularly convenient option.
Compressed Air Applications Manual | Selection of material and pipe system Product range The BEKOFLOW® polybutene (PB) pipe system is distinguished by a broad range of pipes from d 16 to d 110, coiled or in straight lengths, including fittings and outlet connectors. Installation of the BEKOFLOW® system is greatly facilitated by the resistance weld fittings (couplings, elbows, tees, etc.) with their product-coded plug-in connections and the uncomplicated welding tool.
Compressed Air Applications Manual | Pipework design and installation Pipework design and installation For preparing a good design, it is important to be well informed about the actual conditions at the relevant plant. Combining different energy lines in or on the same carrier elements saves both installation time and costs. Since plastic piping is approximately 80 % lighter than metal piping, the installation expenditure is correspondingly reduced.
Compressed Air Applications Manual | Pipework design and installation The design should treat the main pipe, the distribution pipes, and the connecting pipes separately. MP outlets to distribution pipe FP Main pipe For the main pipe (MP) we recommend rigid installation up to d 63. As from size d 75, bending or expansion sections are appropriate. Fixing points should be preferably be located at the outgoing T-piece to the distribution pipe.
Compressed Air Applications Manual | Pipework design and installation Example of a bending section calculation: LDS ∆υ Pipe Easy calculation using the BEKO dimensioning program. = 20 m = 20 k = DN 32 LBS = C x √ LDS x α x ∆υ x d LBS for PB = 32 cm Distribution pipes For the installation of distribution pipes there is a choice of three basic layouts.
Compressed Air Applications Manual | Pipework design and installation Normal mounting on ceilings, walls or other carriers using pipe clamps Installation in a cable duct Inside the cable duct, the pipe can be fixed with cable binders. Rigid or flexible pipe installation Mounting on/along pipework routes using pipe clamps Depending on the type of installation – rigid or flexible – the correct arrangement of fixing points is very important.
Compressed Air Applications Manual | Pipework design and installation Connecting pipes In the case of moist compressed air, the connecting pipes (CP) should be joined to the top of the distribution line (DP). • • Swan neck with BEKOFLOW® pipes Dimensions d 16, d 20 and d 25 T-piece with HWS outlet PB pipe 16x2.2 or 20x2.8 can be bent to swan-neck shape Bending radius min 8xd • In the case of dry compressed air, the connecting pipes (CP) can be joined to the distribution line (DP) in any order.
Compressed Air Applications Manual | Pipework design and installation Duct laying When the pipes are laid in ducts that are then filled with concrete, it must be ensured that the pipes are fully enclosed. The trench should be about 1 m deep and as narrow as possible. Stones and other sharp objects have to be removed. The bottom of the trench should be covered with approx. 10 cm of sand or other fine-grained material.
Compressed Air Applications Manual | Pipework design and installation If the pipe passes through a wall or ceiling, it must be surrounded by a sleeve or by insulation material to separate it from the construction element. The sleeve should protrude slightly at both ends of the construction element. Marking In accordance with VEG 1 § 49 and DIN 2403, pipes have to be marked for the purpose of identification.
Compressed Air Applications Manual | Dimensioning Dimensioning Compressed-air pipe systems, as energy carriers, have to be carefully calculated and dimensioned. If the compressed air pipes are calculated according to the same principles as water pipes, the result will be an energy loss of > 50 %.
Compressed Air Applications Manual | Dimensioning Compressed air demand Allowances for: The compressed air demand is determined on the basis of the specifications for the machine or device connected to the compressed air network. However, in order to ensure that the pipe network is not overdimensioned, it is important to determine the degree of utilization η and take this into account.
Compressed Air Applications Manual | Dimensioning Pipe system dimensioning The network layout determines the length of the main pipe, distribution pipes and connecting pipes. Pipe fittings (elbows, T-pieces, etc.) and valves must be added to the length of the line according to their equivalent pipe length value. The initial dimensioning of the pipe system can be carried out on the basis of Table 1.
Compressed Air Applications Manual | Dimensioning Nomogram The nomogram offers an easy and fast way for determining the correct pipe dimensions. 4. The intersection of line 3 and G shows the appropriate pipe dimension. Example: ∆p = p = V = L = Procedure: 1. Determine pipe length (m) A and flow rate (m³/min) B and join by line 1. 2. Join pressure loss (bar) E and operating pressure (bar) D by line 2. 0.03 bar 6 bar 4.5 m3 /min 120 m Pipe d = 75 3. Join the two intersections of 1/C and 2/F by line 3.
Compressed Air Applications Manual | Dimensioning Table2 Equivalent pipe lengths for fittings and valves Pipe diameter A Fittings Elbows 90 0 16 20 25 32 40 50 63 75 90 110 0.60 0.80 1.00 1.25 1.50 1.80 2.50 1.30 0.40 0.50 0 0.15 0.20 0.25 0.30 0.40 0.50 0.60 0.75 0.90 1.25 T-piece, flow-through 0.10 0.15 0.15 0.20 0.25 0.35 0.45 0.60 0.75 1.00 T-piece, branch 0.50 0.65 0.80 1.00 1.25 1.50 1.90 2.30 2.90 3.50 T-piece, separation 0.65 0.80 1.00 1.
Compressed Air Applications Manual | Flange joints/screwed connections Flange joints/screwed connections Connection: plastic-to-plastic Flange joints or O-ring sealed screwed connections are generally used for the detachable connection of plastic pipes with each other and for the transition from plastic pipes to metal pipes or metal devices (valves, pumps). • • Screwed connections up to d 63 Flange joints up to d 110 Flange joints with O-rings do not require any great tightening torque.
Compressed Air Applications Manual | Material Material Resistance Plastics have become established as suitable materials for modern pipe systems. Plastic pipes have proved their excellence not only for water applications but also for transporting highly corrosive fluids. Hybrid pipes consisting of metal/ plastic or glass have been replaced by cheaper and safer all-plastic pipes with long durability.
Compressed Air Applications Manual | Material Pipe connections Metal pipe connections The following metals are used on PB pipe systems: Alloy Brass DIN Abbreviation 17660 CuZn 39 Pb 2 CuZn 39 Pb 3 Brass, dezincification resistant CuZn 35 Pb 5 (CR-brass) Resistance welding connections Polybutene resistance welding connections are generally suitable for all polybutene-compatible fluids.
Compressed Air Applications Manual | Material Sealing materials (elastomers) Depending on the specific operating and load conditions, the lifetime of sealing materials can vary greatly from that of the pipe material. In the case of compressed air application with mineral oil containing air, NBR or FPM seals have to be used instead of EPDM seals. Sealing material General chemical/physical resistance Max.
Compressed Air Applications Manual | Storage Transport and storage of plastic pipes and fittings Storage - handling of plastic pipes and fittings Right Wrong Plastic is a material that reacts sensitively to impact loads or squeezing during low temperatures. The actual temperature limit depends on the specific material: PP-R PVC-C BEKOFLOW® (PB) + 5 0C - 10 0C Below these temperatures, the pipes and fittings need to be specially protected against mechanical loads from outside.
Compressed Air Applications Manual | BEKOFLOW® HWSG-3 resistance welding tool Resistance welding The welded parts require a cooling period before use. Welding preparation The welding tool and the welding areas must be in a clean and dry condition. Special features • Integrated coding enables recognition of the particular fitting and its dimensions. • Fully automatic welding process after pressing the start button. Therefore, errors due to setting the wrong parameters cannot occur.
Compressed Air Applications Manual | BEKOFLOW® HWSG-3 resistance welding tool Functional description 1. Connect the welding tool to the power supply, all the pilot lights will light up for two seconds. After that, the Power light will be on continuously. 2. Connect the welding cables to the corresponding fitting. Fixing the pipe ends inside the fitting Mark the depth of the pipe insertion into the fitting. The insertion depth of the pipes into the coupling must be marked on both pipes.
Compressed Air Applications Manual | BEKOFLOW® HWSG-3 resistance welding tool Start the welding process by pressing the Start button. The Welding light will blink; the welding start will also be indicated by an acoustic signal. The Ready light of the connected welding channel will blink. 6. Checking the welding results The visual welding indicator confirms the termination of the welding process. The indicator consists of a pin that appears on the coupling when the welding has been successfully completed.
Compressed Air Applications Manual | BEKOFLOW® HWSG-3 resistance welding tool Error signals Cause Remedy 1.
Handbuch Druckluftanwendungen | Symbole Drucklufttechnik Compressors (DIN 28 004, DIN ISO 1219) Measuring equipment / sensors (partly DIN ISO 1219) General Piston compressor Screw compressor General p Pressure gauge p Differential pressure gauge PS Pressure switch T Temperature measurement TI Temperature display / indicator DP Dew point / pressure dew point RH Relative humidity V Volumetric flow (flow rate) v Velocity Turbo compressor Fan, blower Pumps (DIN 28 004, DIN ISO 1219) G
Handbuch Druckluftanwendungen | Symbole Drucklufttechnik Equipment & accessories (DIN ISO 1219) Condensate drains General Receiver Manual drain Non-return valve with reset spring Non-return valve without reset spring Silencer Float drain Time-controlled solenoid valve t Shutoff valve, general 1 2 Electronically level-controlled drain with float 1 2 Electronically level-controlled drain with sensor Solenoid valve Compressed air line (working line) Control cable Compressed air connection S
