Mumbai, Maharashtra, India
Our Products
Maintenance Free Liquid Filled Discharge Dampeners to provide smooth running systems and compliance with API674
API674 pump discharge pulsation dampeners are often a necessary accessory for multi-plunger high pressure reciprocating pumps, as such pumps can produce damaging levels of pulsation and vibration as each slug of liquid is discharged from the cylinder out through the discharge valve and into the pipework.
As the slug of liquid exits the pump cylinder it is will be pushed into a pipeline that is already full of liquid. If the liquid volume in the pipe cannot be fully compressed to make space for this new slug of liquid, or if the pipe containing the liquid will not stretch to give some additional volume, then the pressure in the liquid will rise and a pressure pulse will occur.
How high this pressure pulse goes will depend on how fast the slug of liquid is pushed out it into the pipeline, the compressibility of the liquid already in the pipeline and the stiffness of the pipe material.
The magnitude of the pressure pulses that are generated at the pump, and the forces that they impose on the piping system can be assessed using the guidance given in API674. This specification, produced by the American Petroleum Institute provides conservative guidance that enables the use of simulation analysis to design out these pulsation forces either through modification of the piping system, or by the installation of a pulsation dampener in the discharge pipework, usually positioned immediately downstream of the pump.
This discharge dampener may take one of several forms, however, whichever form is fitted they all have the same thing in common in that they introduce a calculated amount of elasticity into the piping system that will expand and/or contract as each new slug of liquid leaves the pump and enters the piping system, thereby allowing the system to accept each new slug of liquid with minimal pressure rise.
Our liquid filled discharge dampeners offer full compliance with API674 by utilising the compressibility of the liquid volume, and the pressure drop across the equipment.
We can demonstrate compliance with API674 through our full API674 analysis service that simulates the sizing and effectiveness of the solution according to the most rigorous design approach.
Design and manufacture of the equipment will be fully in accordance with your specifications, such that the dampeners become part of the pipeline, and are simply forgotten.
They are a true fit and forget item.
With hundreds of units supplied, and over 30 years of experience in supply, our equipment has a proven track record of reliability and performance.
Carbon steel construction is standard, but other materials such as 304/316 stainless steel, duplex or super duplex steels are available for pressures ranging from as little as 50 BarG and upwards to match the rating of your piping.
If you can design the piping can take the pressure, then we can build a dampener that will fit right in. Whether this just requires some straight forward pressure vessel calculations, or fully detailed Finite Element Analysis (FEA), to prove the design, our in-house engineers have the tools needed to prove the design.
Units can be built to all British, European, American and Indian pressure vessel codes, with CE marking will be applied to equipment that is destined for the European Union.
A few of the fluids that we have built equipment to handle are;
Water, Ammonia, Carbamate, Hot oils, Bitumens, CO2, MEG, TEG, plus various hydrocarbons
Pulsation dampeners are often necessary for multi-plunger high pressure reciprocating pumps which produce damaging levels of pulsation and vibration. These forces can be significantly reduced by the Flo-Dyne non-charged maintenance-free pulsation dampener which is completely filled with the pumped liquid. Our unique spherical in-line design results in optimized low weight and cost and is ideal where rubber bladder or metallic diaphragm types cannot be applied.
Should you require, for our standard dampeners, we can model your system, analyse the pulsation levels and simulate the mechanical response, with the same detail and rigour as needed by API674.
In many cases we can show you that a smooth running system can be achieved with dampeners that are smaller, lighter, and so cheaper, than that required by API674.
Volume
The volume is selected by Flo-Dyne to provide sufficient bulk so that when each plunger discharges its slug of liquid the compressibility of the liquid will absorb a proportion of the pulsation energy. The volume of the dampener must be chosen to be massive compared to the slug of liquid discharged by each plunger on each stroke, and not too large as to be uneconomical for manufacture.
Where required we can offer discharge pulsation dampeners that work upon this feature of compressibility of the volume alone, however such dampeners tend to be both massive and expensive.
The Roots type blower is a positive displacement lobe pump which operates by pumping, or moving, a fluid, usually air, but in some cases a process gas, using a pair of inter-meshing lobed rotors, which have a profile that looks not unlike the number 8. When operating, the fluid is trapped in the outer pockets surrounding the lobes and is carried, or progressed, from one side of the machine to the other.
The lobe shaped rotors (usually two lobes, but it can be 3 or 4) work in tandem and move the fluid, usually air, from one side of the machine to the other. The lobes do not grab, or scoop the air out of the inlet pipe, but rather as they pass the inlet opening they cause a local low pressure area inside inlet port of the machine into which the fluid will then flow. As the rotors continue to turn the fluid that has entered the machine is trapped by the rotors and progressed from the inlet side to the outlet side. On reaching the outlet side the fluid has no choice but to be pushed out into the discharge pipe.
Each time one of the rotor tips passes either the intake or exhaust port, the passing of that tip causes a pressure pulse to be generated. Therefore in the case of a blower with rotors that have 2 lobes there will be 4 pulses for each complete revolution of the pair of rotors (2 pulses from each rotor for each revolution). This allows for a relatively easy estimation of the principal frequency of pulsation that the machine will generate.
Whilst the frequency of the noise from the passing of the rotor tips at the intake and exhaust ports is well understood, there is a second noise mechanism where the fluid tries to pass back through the machine from the high pressure side to the low pressure side by "slipping" around the rotors at their tips. This is an aerodynamic noise mechanism and is less easy to predict as the noise level changes with the speed of the blower and the gap between not only the rotors, but also between the gap between the rotors and the casing.
The noise generated by these two mechanisms are quite different.
The sound from the passing of the rotor past the open inlet port will have a certain frequency, or tone, which on large low speed machines can literally sound like a large helicopter, whilst on smaller machines which operate at higher speeds this tone may sound like a tuning fork.
The aerodynamic sound from the slippage of the fluid back past the rotors is not usually obviously tonal in nature, but rather has a more broadband nature to it, not unlike a valve or pipe exhausting to atmosphere at high velocity.
