Fitting functions
Learn how elbows, tees, crosses, couplings, unions, caps, inserts and outlets change the connection arrangement.
Explore fitting guidesSOCKET WELD / A TECHNICAL LIBRARY
Technical Resources
Learn the connection, compare fitting functions, explore material properties and understand the relevant standards. Practical checklists and working documents support the next step when you are ready.
01 / FIND THE INFORMATION
Start with what you want to understand.
Material properties
Understand the structures, protective films and property differences behind the main material families.
Explore material knowledgeStandards & specifications
Distinguish a fitting standard from a material specification, piping code and inspection-document reference.
Read the standards guide02 / CONNECTION CONCEPT
Understand the socket.
Pipe. Recess. Fitting body.
A socket weld connection receives the pipe end in a recessed socket. The weld is made externally at the connection. The diagrams on this website explain the form; they do not supply installation geometry.
Use the project’s controlled drawing, welding requirements and applicable specification when defining the actual joint.
Explore fitting functionsEXPLORE THE CONNECTION / SELECT A PART
03 / TECHNICAL TERMINOLOGY
Make the description unambiguous.
- Run & branch
- Identify the main connection path and the branch separately when describing a tee or branch connection.
- Equal & reducing
- Describe whether connection sizes are the same or different. List each connection rather than relying on the name alone.
- Material designation
- The exact grade and governing specification identify the material requirement more precisely than a family name.
- Mating component
- The pipe, fitting or assembly that interfaces with the requested component. Include its relevant reference details.
- Drawing revision
- The issue of the drawing that defines the current requirement. Quote both the number and the revision.
- Acceptance requirements
- The inspection criteria, records, marking and project-specific requirements to agree with the order.
A QUICK KNOWLEDGE CHECK
Try three useful distinctions.
Choose an answer to see the explanation. Move through the questions at your own pace; this is a learning exercise, not an engineering assessment.
Where does a socket-weld union separate?
At its central union joint. The ends stay welded to the pipework. Separation takes place at the central union joint without rotating the adjoining pipe runs.
Explore union constructionWhat does duplex describe in stainless steel?
A structure containing austenite and ferrite. Duplex describes the combination of austenite and ferrite in the steel. It is a metallurgical family; corrosion behaviour still varies by grade and environment.
Explore duplex structureWhich reference describes process-piping system requirements?
ASME B31.3. ASME B31.3 addresses process-piping system requirements. EN 10204 describes inspection-document types, while ASTM A105/A105M is a material specification for carbon-steel forgings.
Explore the document layers
INTERACTIVE FUNCTION LAB / SOCKET WELD FITTINGS
What should the connection do?
Turn, branch, join, close or reduce. Choose a function to see the geometry and discover the fitting families behind it.
Choose a view
SW / 01GEOMETRY STUDY
VIEW 01 / 06
Change the direction of the run.
An elbow brings two pipe ends together on different axes. Its angle describes the change in route; the connection sizes describe the pipe ends.
- Two pipe connections
- A defined change in direction
- 45° and 90° are different routing configurations
SW / 02GEOMETRY STUDY
VIEW 02 / 06
Introduce another connection.
Tees, crosses and branch outlets introduce branches through different arrangements. A tee has three connections; a cross has four. An outlet attaches at an opening in the header wall.
- The diagram shows a tee
- The straight-through ends form its run
- The third connection forms its branch
SW / 03GEOMETRY STUDY
VIEW 03 / 06
Continue the line. Define the joint.
A full coupling joins two pipe ends in line through a welded fitting body. A union adds a separable central joint while its socket-weld ends remain attached to the pipework.
- The diagram shows a full coupling
- A common axis connects the two pipe ends
- A union provides a different joint arrangement
SW / 04GEOMETRY STUDY
VIEW 04 / 06
Terminate a pipe end.
A cap has one socket connection and a closed body. It terminates the run as a welded closure rather than providing another through connection.
- One pipe connection
- A closed fitting body
- Termination is distinct from repeated access
SW / 05GEOMETRY STUDY
VIEW 05 / 06
Adapt the connection size.
A reducer insert works with a receiving socket fitting to provide a smaller connection. A reducing coupling provides a size transition through its own connecting body.
- The diagram shows an insert arrangement
- Outer and inner interfaces serve different roles
- A reducing coupling is a separate fitting form
SW / 06GEOMETRY STUDY
VIEW 06 / 06
Define the detail in a drawing.
A controlled drawing can describe an interface or geometry that a general fitting-family name does not express. The drawing and referenced specifications define the component together.
- The highlighted face represents an interface
- Critical features need controlled references
- Concept geometry does not imply a supplied product
These studies explain fitting functions and relative form. They do not define dimensions, installation geometry, performance or availability.
04 / WHEN YOU NEED A CHECKLIST
Put the information into a clear requirement.
Your enquiry checklist
- Fitting family, configuration and quantity for each item
- Each connection size and specified pressure class
- Mating pipe details, where required by the specification
- Exact material grade and applicable specification
- Governing standard and edition
- Drawing number, revision, units and special tolerances
- Required certificates, inspection scope and project records
- Delivery destination and required date
Prepare a structured enquiry
The RFQ form turns your information into an email draft. Review it, attach your documents in your email application and send when ready.
Open the enquiry draft builder →Working offline? Download the checklist and complete it with your project team.
Download checklist (.txt) ↓05 / DRAWING GUIDANCE
Make each reference unambiguous.
Use the current revision
Include the drawing number and revision. Identify any superseded references in your enquiry.
Mark critical details
Call out special dimensions, tolerances, interfaces and any points that require clarification.
List the documents
Reference the drawings and specifications in the enquiry so the attachment set is clear.
06 / WORKING DOCUMENTS
Take the checklist into your project.
Enquiry checklist
A simple offline checklist covering fitting, material, drawing, documentation and delivery details.
Download checklist ↓Line-item worksheet
Blank columns for a multi-item requirement. Open it in your spreadsheet application and add your own project values.
Download worksheet ↓Customer drawing checklist
A checklist of customer drawing references, material specifications and purchase details.
Download drawing checklist ↓07 / TECHNICAL QUESTIONS
Build your understanding.
What does socket weld describe?
It describes a connection in which a pipe end enters a recessed socket and the weld is made externally at the connection. Elbow, tee or coupling describes the fitting’s function and overall geometry.
Where can I compare similar fitting functions?
Each fitting page has a practical guide and product questions. Start with coupling versus union → or branch outlet versus tee →.
Is a material family the same as a material grade?
A family groups materials by broad chemistry, structure or behaviour. A grade identifies a more specific material. Read the material pages for the family’s properties and the differences between related families.
What is the difference between a fitting standard and a piping code?
A fitting standard addresses the component within its stated scope. A piping code addresses the wider system. The Standards page explains these roles alongside material specifications and inspection-document references.
Can I use the illustrations as dimensional drawings?
The illustrations explain the fitting form and connection concept. Use the governing standard and controlled project drawings for dimensional requirements; do not scale website illustrations.
How do I prepare an enquiry after reading the guides?
Use the checklist to gather the fitting, material, connection, standard and documentation details. The RFQ builder prepares a local draft that you review and send from your email application.
Explore the document relationships →THERE IS MORE TO EXPLORE
Follow your curiosity.
Change a configuration. Compare a material. Understand a reference.