There are two ways for branching from the run pipe.

• 1^st is a pipe to pipe branching. Either with reinforcement pad or with the help of standard tee. When we make opening in the pipe for the pipe to pipe branching without using TEE, it will weaken the pipe. To avoid this, additional reinforcement pad is welded to the pipe, this type of branch connection is fabricated at the site.
• In the second method, instead of additional reinforcement pad, you used a heavier specially designed branch that works as a Self-reinforced branch.
• This Specially design branch connection is known as “Olets.”
• Whenever branch connections are required in size where reducing tees are not available and/or when the branch connections are of smaller size as compared to header size, Olets are generally used.

• Self-reinforced branches (Olets) are designed as per Process Piping Code ASME B31.3
• Other standard available is MSS SP-97 that is Manufacturers Standardization Society
• Most commonly used olets are;
  • Weldolet, Sockolet, Thredolet, Elbolet and Nipolet,
  • Special Olets such as Latrolet, Flexolet and Coupolet are also used sometimes. You will see each of them in next slides.

• Self-reinforced branches (Olets) are designed as per Process Piping Code ASME B31.3
• Other standard available is MSS SP-97 that is Manufacturers Standardization Society
• Most commonly used olets are;
  • Weldolet, Sockolet, Thredolet, Elbolet and Nipolet,
  • Special Olets such as Latrolet, Flexolet and Coupolet are also used sometimes. You will see each of them in next slides.

Weldolet

• Weldolet is 90° branch connection
• It Comes in full size or reducing size (Full size is when you take branch of the same size as run pipe size for example 3 inch to 3 inch. And reducing size is when branch size is less than run pipe size 3 inch to 1 inch)
• Weldolet’s end is suited for the butt welding connection.

Sockolet

• Sockolet is same as weldolet but with socket end.
• It is 90° branch connection
• Comes in full size or reducing size
• End connection is suited for socket welding

End connection is suited for socket welding

Thredolet

• Thredolet is 90° branch connection comes with threaded end connection
• It also Comes in full size or reducing size
• End connection is suited for threaded joint

Elbolet

• Elbolet is a special type of olets which fits on elbow surface. It is 90° branch connection and comes in different types of ends that suit for butt welding, socket welding and threaded joint

Nipolet

• Nipolet is weldolet with extended pipe body. As you can see in the image
• It is 90° branch connection and comes in different types of ends that suit for butt welding, socket welding or threaded joint

Latrolet

• There are some special olets also used in piping such as
• Latrolet that is used for taking branch which is not at 90 degrees to run pipe.
  • Latrolet comes in a 45°or any other special degree as required by purchaser
  • End connections of a Latrolet can be butt welded, socket welded or threaded.

Coupolet

• Coupolet is Olets with female NPT thread that uses for low-pressure This will reduce use of one sockolet and one coupling.

Sweepolet

• Sweepolet is used for large size branch connection.
• It provides smooth flow transition from run pipe to branch pipe.
• Sweepolet is used in piping header and pressure vessel when smooth flow transition is necessary and standard tee cannot be used.

ASME flanges have a minimum four bolt hole and for higher diameter flanges, the number of bolt holes is always in multiples of four. Selection of number bolt holes depends on the factor such as

• Size of the flange
• Working pressure
• Working temperature
• Flange material

Different Kinds of Fasteners Used in Piping

Stud Bolt

Stud has a thread on full lengths or at both ends. As shown in images. It is having three components if washers are not used (two nuts and stud). If you used washer it would become five. Sometimes additional nuts are used for hydraulic tensioning with larger size stud.

The length of stud bolt should be enough to cover entire Nut plus 1.5 to 3 threads exposed. Long studs must be avoided as it increases the chance of corrosion and other damage to exposed threads, which would make subsequent removal difficult. ASME B16.5 gives the required size of the stud. Length of the stud depends on the type of gasket and the maximum exposed thread requirements.

Machine Bolt

Bolts have a thread at one end and hexagonal head on another end. See the image below. In the process, piping bolts are used with lower strength flange types such as GRE/GRP, bronze. Usually, washers are used with bolt to prevent excessive load to the flange.

Nuts

Commonly Hexagonal Heavy-series nuts used with studs. The nonbearing face of a nut is chamfered, while load Bearing face is finished with a washer face or may be chamfered.

Washers

A washer is a thin plate with a hole at center. Washers distribute the load on flange face; this prevents damage to the flange. Non-metallic flange required washers due to this reason. Different types of washers are used such as Flat, Splits, and Conical Springs.

Conical washers are special washers. Also known as Belleville Springs washers. It Keeps bolted joints tight in an area where vibration, differential thermal expansion, and bolt creep present. These conditions can change the load on a stud which may result in a loose connection. Conical washers provide a spring effect and prevent loosening of a stud. This washer provides High spring loads with small deflections.

Stud Bolt Specification & Standard

Various ASME standards are used for stud bolts and nuts to manufacturing bolting material. List of such standard is given below.

• Diameter and Lengths of the stud and bolt are covered in ASME B16.5 & B16.47
• ASME B1.1 Unified Inch Screw Threads (Cores and Fine thread series- normally Cores thread series is used for stud used in piping)
• ASME B18.2.1 for Square and Hex Bolts and Screws
• ASME B18.2.2 Square and Hex Nuts
• ASME B18.21.1 Lock Washers
• ASME B18.22.1 Plain Washers

Stud Material Grades

Bolting material can be divided into three group

• High Strength
• Intermediate strength
• Low Strength

Stud

List of ASTM Material grade used for manufacturing stud is given in ASME B16.5, which is the Standard for the flanges.

• For high temperature and pressure services ASTM A193 Gr B7, B7M, B5, B8 are used.
• For low-temperature services ASTM A320 Gr L7, L7A, L7B are used.
• ASTM A354 Gr BC, BD is material grades for alloy steel quenched and tempered studs and bolts.
• For special application, ASTM A540 Gr B21 to B24 are used.

Out of these grades, most popular material grades are ASTM A193 Gr B7 & B7M.

Nuts

Nuts may be machined from the same material as stud or may be of a compatible grade of ASTM A194

• ASTM A194 standard lists the compatible material grades for nuts that used with stud & bolt.
• Most widely used material grades are ASTM A194 Gr 2,2H,2HM,8,8M

Washer

Common material grade used for washer manufacturing are

• ASTM F436, ASTM F844, ASTM F959
• If not specified washer can be manufactured from any compatible grade material

Coating on Stud Bolts and Nuts

Sometimes Bolting components are coated with different coating materials to improve its corrosion resistance. This will reduce maintenance cost. Common coatings are

• Chrome Plating
• Galvanizing
• Xylan
• PTFE
• Zinc

Gaskets

In piping, a Gasket is sealing material placed between connecting flanges to create a static seal, which will maintain the leakage proof sealing in all operating conditions. Different types of gaskets are used to achieve the leak proof sealing between the pipe flange. The primary function of gaskets is to seal the irregularities of each face of the flange so that there will be no leakage of the service fluid from the flange joint.

Types of Gaskets

There are three types of gaskets used in process piping.

• Non-Metallic
• Metallic
• Composite

Chances are there that you already know this. But there is no harm to refresh the memory.

Valve is a device that regulates, controls or directs the flow of a fluid by opening, closing, or partially obstructing fluid flow. Sound bit complicated? Ok, let me further simplified this.  A valve is a mechanical device that controls the flow and pressure of fluid within a system or Process.  So basically, it controls flow & pressure.

Types of Valves

In piping following types of valves are used depending on the requirements. The cost of Valve in the piping system is up to 20 to 30% of the overall piping cost. And the cost of a given type and size of the valve can vary 100%. It means that if you choose ball valve over butterfly valve for the same function. It can cost you more. So, the selection of valves is essential to the economics, as well as operation, of the process plants.

• Gate Valve
• Globe Valve
• Check Valve
• Plug valve
• Ball Valve
• Butterfly Valve
• Needle Valve
• Pinch Valve
• Pressure Relief Valve

Gate valve

Gate valve is the most common type of valve in any process plant. It is a linear motion valve used to start or stop fluid flow. In service, these valves are either in fully open or fully closed position. Gate valves are used in almost all fluid services such as air, fuel gas, feedwater, steam, lube oil, hydrocarbon, and all most any services. Gate valve provides good shutoff.

Globe Valve

Globe valve is used to stop, start, and regulate the fluid flow. Globe Valves are used in the systems where flow control is required and leak tightness is also necessary. Globe valve provides better shut off as compared to gate valve and it is costlier than gate valve.

Check Valve

The check valve prevents backflow in the piping system. The pressure of the fluid passing through a pipeline opens the valve, while any reversal of flow will close the valve.

Plug valve

Plug valve is Quarter-turn rotary motion Valve that uses a tapered or cylindrical plug to stop or start the flow. The disk is in plug shape, which has a passage to pass the flow. Plug valve used as on-off stop valves and capable of providing bubble tight shutoff. Plug valve can be used in vacuum to high-pressure & temperature applications

Ball Valve

A Ball valve is a quarter-turn rotary motion valve that uses a ball-shaped disk to stop or start the flow. Most ball valves are of the quick-acting type, which requires a 90° turn of the valve handle to operate the valve. The ball valve is Smaller and lighter than a gate valve of same size and rating.

Butterfly Valve

A Butterfly valve is a quarter-turn rotary motion valve, that is used to stop, regulate, and start the flow. Butterfly valve has a short circular body. Butterfly Valve is suitable for large valve applications due to Compact, lightweight design that requires considerably less space, as compared to other valves.

Needle Valve

Needle valves are similar to a globe valve in design with the biggest difference is the sharp needle like a disk. Needle valves are designed to give very accurate control of flow in small diameter piping systems. They get their name from their sharp-pointed conical disc and matching seat.

Pinch Valve

The pinch valve is also known as clamp valve. It is a linear motion valve. Used to start, regulate, and stop fluid flow. It uses a rubber tube, also known as a pinch tube and a pinch mechanism to control the fluid. Pinch Valve is ideally suited for the handling of slurries, liquids with large amounts of suspended solids, and systems that convey solid material pneumatically.

Pressure Relief  Valve

A pressure Relief valve or pressure safety valve are used to protect equipment or piping system during an overpressure event or in the event of vacuum. This valve releases the pressure or vacuum at pre-defined set pressure.

Valves Functions

Valve serve a various function within the piping system.  Such as

• Stopping and starting a fluid flow. Depending on whether a valve is open or closed, it let pass the process fluid or halt the fluid.
• Throttling the fluid flow. Some of the valves let you throttle the fluid depending open % of total opening. Lesser the opening higher the throttling and otherwise.
• Controlling the direction of a fluid flow. Multiport valve lets you decide the way fluid will go.
• Regulating a flow or pressure within the piping system. Some of the automatic control valves maintain the flow and pressure within the system by adjusting opening and closing.
• Relieve pressure or vacuum from the piping system and equipment. Pressure and vacuum relief valve safeguard the process system from overpressure and during vacuum condition.