Some Tips and Notes (1)
Measuring flow
Baron Kelvin (William Thomson) (British Scientist) once said..
"When you can measure what you are speaking about and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind."
In other words, you cannot manage what you cannot measure and nowhere is that more true than in the measurement of flow.
Difference between an Orifice Plate and a Restriction Orifice
An Orifice Plate is used to measure flow, while a Restriction Orifice is used to drop upstream pressure of a system. It is similar to an orifice plate but is thicker. While passing the fluid through thick plate energy is lost in friction and heat resulting considerable pressure drop.
Dimensions of Square Edge Orifice Plates for ASME B16.36 RF Orifice Flanges
Dimensions of Restriction Orifice Plates for ASME B16.5 RF Flanges
Jetty
The words pier and jetty are often used interchangeably, such as LNG pier or LNG jetty, both of which refer to a fixed offshore or nearshore platform that usually rises above the water on pile foundations.
In the oil and gas industry, the term Jetty refers to the "Pier" type, i.e. a platform above water used for the transshipment of oil, gas, minerals and other cargo.
Many of these Jettys are equipped with Marine Loading Arms for loading and unloading sea and inland waterway ships.
Hot Work Permit
Hot Work is a Life-Critical Procedure and indicates that Hot Work in the chemical industry, among others, is high-risk work.
The risk of Hot Work in a chemical plant is fire and explosion. Fire and explosion can cause injury to employees, cause environmental damage and material damage to the installations and buildings. It is wise to apply the correct control measures at the time that Hot Work has to be carried out to prevent fire and / or explosion.
Welding & cutting equipment must, when absent and at the end of a job
- Be left de-energized and depressurized up to the main switch/connector.
- The bottle set must be placed outside the installation during prolonged absence.
- Secure gas bottles, preferably use bottle cart.
- All equipment, cables, connections and hoses and surfaces above and below the work surface should be checked for fire hazard/defectiveness.
Hot Work Permit
The permit itself exists in many versions, and many companies use their own design. In the past, the permits were filled in by means of a paper version, nowadays this is often done electronically, where the software can help to correctly describe all the steps.
Nominal Pipe Size
- A question was put to the PM Engineer (PME) staff (one of SUPPLY HOUSE TIMES sister magazines) asking how nominal pipe size came to be. Here is the answer provided by PME Editorial Director Julius Ballanco.
- The person directly responsible for the nominal pipe size was a gentleman by the name of Robert Briggs. Briggs was the superintendent of the Pascal Iron Works in Philadelphia. In 1862, he wrote a set of pipe specifications for iron pipe, and passed them around to all of the mills in the area.
- Realize that in 1862, the United States was engaged in the Civil War. Each pipe mill made its own pipe and fittings to its own specifications. Briggs tried to standardize the sizing, which would also help the war effort. The pipe and fittings would be interchangeable between mills. This was rather novel in 1862.
- The pipe standards went on to become known as the "Briggs Standards". They eventually became the American Standards, and finally the standards used for modern day pipe.
- The current ASTM A53 Steel Pipe Standard uses basically the Briggs Standard for pipe sizes 1/2 inch through 4 inch. You will notice that after 4 inches, pipe starts to get closer to the actual dimension used to identify the pipe.
- So, you are probably asking, where did the sizes come from ?. Well, they were the sizes of the dies used in Pascal Iron Works. Briggs made everyone adjust to him. Hence, the name "nominal" pipe size came about, meaning "close to" or "somewhere in the proximity of" the actual dimension.
I found the story behind Nominal Pipe Size on..
www.supplyht.com / Supplyhouse Times
Birmingham Wire Gauge
And time ago, I was involved by Eddy Current inspection of heat exchangers.
Most companies have a partner (third party) to do the special inspection. For the third party, it is important to know the outside diameter, the wall thickness, the number and the lengths of the tubes. OD minus 2 times the wall thickness is the Inside Diameter (ID), and so the third party knows which sensor to use. Of course, the length of the tubes is also important for the length of the sensor.
In one of the bundle tube specifications, the wall thickness was indicated by BWG14.
At first I didn't know what it meant.
That is easy to explain, because all dimensions of other bundle exchangers were given in inches and millimeters, but not in Birmingham Wire Gauges.
So BWG14 tells us that the wall thickness of the bundle tubes is 0.083 inches or 2,108 mm.
Smooth finish
Is it suitable for spiral gasket and non metallic gasket?
For what kind of application is this type?
The above questions are often asked. I try to give a correct answer.
Smooth finish flanges are more common for low pressure and/or large diameter pipelines and primarily intended for use with solid metal or spiral wound gaskets.
Smooth finishes are usually found on machinery or flanged joints other than pipe flanges. When working with a smooth finish, it is important to consider using a thinner gasket to lessen the effects of creep and cold flow. It should be noted, however, that both a thinner gasket and the smooth finish, in and of themselves, require a higher compressive force (i.e. bolt torque) to achieve the seal.
You may have probably seen this comment..
Machining of gasket faces of flanges to a smooth finish of Ra = 3.2 - 6.3 micrometer (= 125 - 250 microinches AARH)
AARH stands for Arithmetic Average Roughness Height. It is used to measure the roughness (rather smoothness) of surfaces. 125 AARH means 125 micro inches will be the average height of the ups and downs of the surface.
63 AARH is specified for Ring Type Joints.
125-250 AARH (it is called smooth finish) is specified for Spiral Wound Gaskets.
250-500 AARH (it is called stock finish) is specified for soft gaskets such as NON Asbestos, Graphite sheets, Elastomers etc. If we use smooth finish for soft gaskets enough "biting effect" will not occur and hence the joint may develop leak.
Sometimes AARH is referred also as Ra which stands for Roughness Average and means the same.
Extended Valve Bonnet
Bonnet extensions are required in valves where they are subject to high or low temperatures, which can affect the integrity of the stem seals.
The extended bonnet serves to isolate the packing box from the high or low temperature zone, which helps maintain the integrity of the stem seal and the operation of the valve. In some cases, an extension may be required to place the packing box outside the insulation.
150lb - 150lbs - 150# - Class 150
LB is the origin of the Latin word libra (weighing scale), and describes a Roman unit of mass similar to a pound.
The full expression was librapondo, and we have invented acronyms such as..
lb = one pound, lbs = more pounds, # = Abbreviation for pound
Text below is from www.worldwidewords.org copyright © of Michael Quinion
The form lb is actually an abbreviation of the Latin word libra, which could mean a pound, itself a shortened form of the full expression, libra pondo, "pound weight". The second word of this phrase, by the way, is the origin of the English pound.
You will also know Libra as the astrological sign, the seventh sign of the zodiac. In classical times that name was given to rather an uninspiring constellation, with no particularly bright stars in it. It was thought to represent scales or a balance, the main sense of libra in Latin, which is why it is often accompanied by the image of a pair of scales.
Libra for a pound is first found in English in the late fourteenth century, almost at the same time as lb started to be used. Strictly speaking again, this was the Roman pound of 12 ounces, not the more modern one of 16. And just to consolidate my reputation for careful description, modern metrologists, scientists who study units of measurements, would prefer that we don't use lbs at all; in scientific work, all units are singular.
Incidentally, another abbreviation for libra became the standard symbol for the British pound in the monetary sense. In modern times it is usually written £, an ornate form of L in which a pair of cross-strokes (often just one these days) were the way that a medieval scribe marked an abbreviation. The link between the two senses of pound, weight and money, is that in England a thousand years ago a pound in money was equivalent to the value of a pound of silver.
Difference between ASTM A106 Grade A, B and C
Grade A has lower carbon content, is a softer steel and easier to bend. Grade B has higher carbon content and tensile strength than Grade A and Grade C has higher tensile strength than Grade B.
TASTM A106 Grade A 0.25% C (max) 0.1% Si SMYS 30ksi
ASTM A106 Grade B 0.30% C (max) 0.1% Si SMYS 35ksi
ASTM A106 Grade C 0.35% C (max) 0.1% Si SMYS 40ksi
SMYS = Specified minimum yield strength for steel pipes manufactured in accordance with a stated specification. This is a commonly used term in the oil and gas industry for steel pipes under the jurisdiction of the US Department of Transportation.
ksi = is the abbreviated form of the unit “kilopound per square inch” which is used to measure pressure. It is actually equal to 1000 psi (pound-force per square inch/ lbf/in^2). psi is a British unit defined as the pound-force (force exerted by gravity on a British pound) exerted on an area of one square inch. ksi is not widely used to measure gas pressure, but it is used primarily in materials science to measure things like tensile strength (maximum stress an object can withstand), which is measured using a large number of “psi”.
Spade/Spacer handles
ASME B16.48 says..
spade handles may have no openings.
Spade closed position
without lifting hole
Ring Spacer open position
with lifting hole
For spades, which can be lift up by people that's no problem, but for a spade that weighs hundreds of kilograms, a lifting ability is needed. So it is usual, that from a certain weight and size, a hole at the top of the handle is made to give a lifting possibly.
Many companies have their own rules, about the implementation of a spade handle, so there are many different types and designs.
Raised Face Blanks
ASME B16.48 says..The gasket seating surface finish and dimensions for raised face line blanks shall be in accordance with ASME B16.5. A raised face may be specified at the option of the purchaser.
Raised Face would add machining time and complexity so the price would be higher. Call this the Bugatti or Rolls Royce of the line blind world.
Personally, I have seen that version once or twice somewhere. The version without Raised Face is the default and is used everywhere
Easy way to make a 1/16" Gap...
Have you ever seen a Socket Weld contraction ring?.
It is a split ring that is engineered and designed to give a pre-measured 1/16" minimum gap for socket welds. Made from a certified stainless steel, and resists corrosion from chemicals, radioactive materials and water. Once inserted into the fitting the ring becomes a permanent part of the joint. It will not rattle or vibrate even under extreme pressure.
nother manner is the applying of in water-soluble board. Make rings with a hole punch with outside and inside diameter of the pipe. Insert the ring into the flange or fitting and after hydrotesting there is no ring anymore
For both solutions, ask your customer for permission.
Difference between heat and lot
Heat refers to the primary melting of a metal. The heat determines the chemistry, unless the parts of the heat undergo additional treatment or refinement.
A lot or batch refers to the amount of similar items made at the same time using material of the same heat using the same manufacturing process.
Center-Line and EL symbol
I have learned, to apply a Elevation symbol and a Center-Line symbol to a isometric. Namely, the Center-Line symbol at the end of the centerline, and on that line the Elevation symbol, followed by the elevation-number.
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The sign on the left shows the centerline symbol. Tip for AutoCad users.. use the CDT font, lower case Q. |
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The sign on the left shows the Elevation symbol. That sign, you will see on almost every isometric. |
Dual Certified Pipes
It has become increasingly common for manufacturers to supply dual certified pipe. For example, dual certified stainless steel ASTM A312 TP304/304L and TP316/316L are widely available. Dual certification means that the material meets the maximum carbon limit of L grades, which is 0.03% C, while also meeting the higher mechanical properties of standard grade pipe.
Low carbon (L) stainless steel is used to minimize the risk of sensitization during welding. Sensitization is the formation of chromium carbides along the grain boundaries, resulting in a loss of corrosion resistance. The low carbon levels limit the amount of chromium carbides that are formed, thereby limiting the depletion of chromium along the grain boundaries. Therefore, grade 304L offers better corrosion resistance, especially when welding.
Can Ring Joint Gaskets be reused?
Simple answer - NO
The link below will give you the answer to that...
Can Ring Joint Gaskets be reused?
Improper Flange Connections
The picture show a improperly bolted flange, because two bolts are too short, and the nuts are not completely on the bolts.
This means that the joint may not be as strong as it should be. Flanges are designed so that the entire nut-bolt combination holds the forces on the flange. If the nut is only partially screwed onto the bolt, the connection may not be strong enough.
Cutting thread on a pipe
You knew that...?
At the smallest sizes, the amount of wall lost during threading actually equals approximately 55% of the original pipe wall.
Cavity relief Ball valve
Years ago, when I was working for Shell, I first heard about a Cavity relief ball valve in cryogenic service. Well what could it be?.
SHELL MESC stipulates a pressure equalizing hole of at least 3 mm in the ball. It states that the ball valve must have an automatic way to relieve overpressure. Cryogenic standard BS 6364 tells us the same.
The use of self-venting ball seats according to EEMUA 182 specifications is another solution. The surplus pressure spews out around the ball seat.
We must always keep in mind that cryogenic gases are very sensitive and leakage can pose a serious risk. In this sense, a cryogenic valve is a guarantee for the proper functioning of the system.