Can you design and specify a complete steam plant?
Absolutely, we have a design and spec team who will look after your project from start to finish.
What steam pipe size do I need to install to get a given flow at a certain steam pressure?
Refer to the technical references section (pipe size capacities)
What is the ideal steam velocity when sizing steam lines?
Two answers – for direct steam injection systems – around about 35m/sec. For closed loop systems approx 25 – 30m/sec.
What is the ideal steam system pressure for direct steam injection systems?
Approx 350 kPa because the noise is reduced compared to a higher pressure and the steam has a chance to fully condense.
Should I take all my steam take-off lines off the top of the steam line?
Absolutely. Condensate will always be flowing in the bottom section of a saturated steam line and needs to be drained away by a steam trap rather than being fed into a process.
How high can the condensate be lifted after the steam trap?
First of all do not consider the steam pressure before any control valve or pressure reducing valve. The important pressure is after the control valve at full load. For every 10kPa pressure, the condensate can be lifted 1m.
How do I size a condensate line?
Generally condensate lines are sized on a velocity or a pressure drop based on approx 80 Pa per metre of travel, with an allowance made for flash steam that forms after the steam trap. Refer to the technical references section (condensate pipe sizing)
What types of steam traps are there?
Mechanical, Thermostatic, Thermodynamic and Fixed Orifice.
Do I need a cooling leg before a balanced pressure or bimetal trap?
Absolutely. The cooling leg acts like a receiver and as the trap internals react to the temperature of the condensate, the receiver holds the condensate, not the process or application.
Should Hospital Sterilisers have the steam separator fitted with a balanced pressure trap?
The Australian Standards say it is allowed. From a steam efficiency point of view, our policy is they should never be used for this application.
Are there any general rules of thumb for steam trap selection?
Yes. For main line drainage and header drainage, use a bucket trap or a thermodynamic trap. For process equipment such as heat exchangers / cookers, use either a bucket trap or a float trap either should have an inbuilt air vent. For steam separators, use either a bucket or float trap. For draining the jackets of Hospital Sterilisers, use a balanced pressure trap. For draining long condensate droppers (as generally found in the petrochemical industry) use bimetal traps. For turbine drainage, use a bucket trap or a fixed orifice trap.
Why in the majority of times, is the pipe size downstream of a pressure reducing valve larger than the upstream pipe size?
From steam tables it can be seen that the volumetric area of steam for a given amount is greater at a lower pressure. If the pipe was not increased in size after the reducing valve, the velocity of the steam could be so great to reach critical flow, resulting in severe noise, erosion and insufficient steam flow.
Why do I need a safety relief valve downstream of a pressure reducing valve?
All equipment has pressure limitations and in some systems, due to a low limitation they require the steam pressure to be reduced and the equipment protected, should the pressure reducing valve fail.
How should I size the safety valve?
Firstly, not on the steam flow calculation. The valve should be sized on the maximum flow rate of the pressure reducing valve, should it fail in the full open position.
What is the difference between a safety valve and a safety relief valve?
There are a few trains of thought here. We understand a safety valve is generally for pressure vessels and has stricter tolerances and settings compared to a “general” safety relief valve which is generally supplied on non-pressure vessels.
What is the ideal pressure drop across a control valve?
For direct steam injection applications 35%. For closed loop systems a max of 25%.
What does “critical pressure drop” mean when referring to control valves?
Critical Pressure Drop means, if the valve is undersized or the flow is greater than 42%, the valve is at maximum capacity.
Why do some steam companies say “if you have a temperature control application, I need a condensate pump?”
Because they are wrong ! there are 6 solutions or answers to this problem and at Armstrong, we will offer the correct one for the application – not just offer a single expensive solution.
At what pressure should I design my flash vessel for?
This is dependent upon the maximum amount of condensate returned to the flash vessel and the temperature of the condensate. Basically the system determines what the flash steam pressure will be. A rule of thumb is to size everything on 10% of the condensate flashing into steam.
Do I need an air vent on my Jacketed Pan?
The old style pans have a steam jacket, all in one piece. Air will enter the pan on startup and will form on the opposite side to the steam entry and will reduce the efficiency of the system by as much as 60 %. So always install an air vent on the old style pans, opposite the steam inlet. On the newer pans, they are manufactured with a passageway for the steam and any air is pushed through the jacket to the steam trap. The steam trap therefore requires an inbuilt air vent.
Do you do steam training?
Most definately, in Australia we offer various course such as full one day steam system courses, and a 1hr steam system safety course in accordance with the new WHS Act and Regulations 2010. We also will design a course for individual companies. View all of our training resources.
Where is steam mentioned in the WHS Act and Regulations 2010?
With the new National legislation, steam is mentioned in various parts of it with particular references to safety, liability and training.
We want to support an Australian Company, is Armstrong Flow Control Australian?
Armstrong Flow Control is a long established privately owned Australian Company with strong customer and supplies relationship.
The company originated in Australia back in 1972 distributing products manufactured by USA company, Armstrong Machine Works, which was founded in 1904 and today is still owned by the same family.
Do you have International connections and support?
Yes - Armstrong Flow Control has long standing relationships which allows us to offer an extensive range of quality products or services with first class support.