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Description
A 45 degree elbow changes the direction of a line by 45 degrees. It is welded to the pipe with a full penetration butt weld, so there is no thread to loosen and no socket cavity to trap fluid — the fitting and the pipe become one continuous pressure boundary.
We manufacture carbon steel 45° elbows in ASTM A234 WPB to ASME B16.9, in long radius. Long radius is the standard configuration; a short radius 45° is not a standard B16.9 item and is made to drawing where the layout requires it.
The 45° elbow is the fitting that makes a routing work: when a line only needs a partial change of direction, or when two 45° elbows with a spool piece are used instead of a single 90°.
Butt weld fittings carry no pressure class. Wall thickness comes from the pipe schedule, so the schedule has to be stated at quotation stage. Every shipment leaves with an EN 10204 3.1 material certificate, traceable to the heat number.
45° Butt Weld Elbows (Long Radius)
Specifications
| Item | Specification |
|---|---|
| Product | 45° butt weld elbow, long radius (LR); short radius and non-standard radius made to drawing |
| Material | ASTM A234 WPB (carbon steel) |
| Standard | ASME B16.9 (long radius); short radius to drawing |
| Centerline radius | LR = 1.5 × NPS |
| Size range | NPS 1/2" to 24" as standard in seamless construction; larger sizes in welded construction on request |
| Wall thickness | Specified by pipe schedule — SCH 10 / 20 / 40 / 80 / 120 / 160 / XS / XXS |
| Pressure rating | Butt weld fittings do not carry a pressure class. Capability is determined by the pipe schedule, the material and the applicable piping code, such as ASME B31.3 |
| End preparation | Bevelled to ASME B16.25 |
| Manufacturing | Seamless, hot formed, as standard up to NPS 24; welded construction for larger sizes |
| Heat treatment | Per ASTM A234 WPB — normalised, normalised and tempered, or stress relieved, as specified |
| Surface | Black as standard; shot blasted, oiled or painted on request |
| Certification | EN 10204 3.1 material test certificate, traceable to heat number |
| Lead time | Standard sizes in regular material take 7-15 days; non-standard sizes, non-standard schedules and special requirements take 20-35 days. Sea freight to the Gulf is additional and depends on the destination port. Lead time is confirmed in writing with your quotation and is subject to the production schedule at the time of order. |
| HS code | 7307.93 |
Applications
- Process lines that need a partial change of direction rather than a right-angle turn
- Two 45° elbows with a spool piece, where a single 90° would be too abrupt for the service
- Pipe racks and skids, where a line has to route around equipment or an existing header
- Steam, condensate, cooling water and utility lines
- Loading and unloading lines at terminals, where the layout angle rarely works out to a right angle
- Onshore and offshore oil and gas piping, with material and coating confirmed for the service
- EPC contractors and overseas infrastructure projects — water transmission mains, district cooling networks, airport and industrial park piping, supplied to the project specification and the document package your QA team requires
Samples, Third-Party Inspection and Test Records
Sample pieces can be produced before the batch runs, so that dimensions, bevel profile and fit-up can be checked on your side first. Sample cost and delivery time are advised with the quotation, based on size and material.
Buyer-nominated inspection is supported. SGS, BV, Intertek or your own inspector can witness dimensional checking, marking, coating and container loading at the production site, and we provide the documents and site access needed for the visit. Where a visit is not practical, the same checks can be followed through a live video walkthrough. Third-party inspection fees are normally carried by the buyer.
Non-destructive testing and hydrostatic test records are available on request and can be shipped with the order, together with the EN 10204 3.1 material certificate, the heat number and marking list, dimensional records, packing list and certificate of origin. Tell us at enquiry stage which records your project requires, and they are included in the quotation.
45° or 90°
45° elbow 90° elbow
Direction of turn 45 degrees 90 degrees
Standard ASME B16.9 (long radius) ASME B16.9 (long radius); ASME B16.28 (short radius)
Pressure drop Lower Higher
Erosion at the turn Less More
Run length for the same offset Longer Shorter
Typical use Partial direction changes, offsets, routing around obstacles Right-angle turns, headers, risers, compact layouts
Two 45° elbows with a spool piece turn a line through 90 degrees more gently than a single 90° elbow, at the cost of one extra weld. On abrasive or high-velocity service that trade is usually worth making.
For a right-angle turn, see 90 degree elbows. For a U-shaped run, see 180 degree return bends.
FAQ
Q1: Is a 45 degree elbow long radius or short radius?
ASME B16.9 covers the 45° elbow in long radius, and that is what we supply as standard. A short radius 45° is not a standard catalogue item under B16.9 or B16.28; where the layout needs one, it is fabricated to your drawing.
Q2: How is the center-to-end dimension of a 45 degree elbow determined?
It is taken from the ASME B16.9 tables for the size and schedule, not calculated by rule of thumb. Send us the size and schedule and we will confirm the dimension at quotation stage, so the spool take-off is right the first time.
Q3: Can two 45 degree elbows replace a single 90 degree elbow?
Yes, and it is common practice on lines where flow matters. The turn is gentler, so pressure drop and erosion both drop. The take-off changes though — two 45s plus a spool is not the same length as one 90 — so the layout has to be recalculated from the standard dimensions.
Q4: Does using two 45s instead of one 90 change the pressure drop?
It lowers it. A 45 degree turn sheds less energy than a 90 degree turn, and the space between the two elbows lets the flow re-establish before the next change of direction. The trade-off is one more girth weld to make and inspect.
Q5: Are 45 degree elbows available in stainless steel or alloy grades?
Carbon steel to ASTM A234 WPB is our standard supply. Stainless grades such as ASTM A403 WP304 and WP316L, and alloy grades such as ASTM A234 WP11 and WP22, are supplied on request against the same dimensional standard.
Q6: What wall thickness should I specify for a 45 degree elbow?
The same schedule as the connecting pipe. There is no separate thickness table for the elbow: the bore and the wall follow the pipe. State the schedule at quotation stage and the fitting is matched to it.
Q7: Are the ends bevelled, and can I get a different bevel?
Standard supply is bevelled to ASME B16.25, which fixes the bevel angle, the root face and the land. If your welding procedure calls for something else, send the bevel detail with the enquiry.
Q8: Can 45 degree elbows be supplied in welded construction?
Yes, for sizes above the standard seamless range. Welded construction is the normal route for large diameters; the seam weld is examined the same way as any welded fitting, and RT can be specified at quotation stage.
Q9: Is a 45 degree elbow suitable for piggable lines?
A standard long radius 45° elbow to ASME B16.9 keeps the bore full and is piggable. What stops a pig is not the 45 degree angle — it is a mitred bend, a short radius fitting in a tight size, or a bore step at a weld where the wall thicknesses do not match.
Q10: Can you add our own item code or tag to the fittings?
Yes. Standard marking covers the grade, size, schedule, standard and heat number, and we can add your item code, a low-stress stamp or a paint stencil. Tagged and labelled packing for project orders is arranged on request.
Q11: What sizes and pressure ratings are available for 45 degree butt weld elbows?
NPS 1/2 inch to 24 inch as standard in seamless construction, with larger sizes in welded construction on request. Wall thickness is specified by pipe schedule. Sizes and ratings outside this range can be reviewed against your drawing. The exact range confirmed for your order is stated in the quotation.
Q12: How is the wall thickness determined for 45 degree butt weld elbows?
Butt-weld fittings do not carry a pressure class. Wall thickness is specified by the pipe schedule (SCH 10 / 20 / 40 / 80 / 120 / 160 / XS / XXS), and the schedule must be stated when you request a quotation.
Q13: What is the lead time for 45 degree butt weld elbows?
Standard sizes in regular material normally take 7-15 days. Non-standard sizes, special materials and custom orders take longer. The exact lead time for this product is given in the specification table on this page and is confirmed in writing with your quotation. Sea freight to the Gulf is additional and depends on the destination port. All lead times are subject to the production schedule at the time of order.
Q14: Is there a minimum order quantity for 45 degree butt weld elbows?
There is no fixed minimum. Standard items can ship from a single pallet, and custom production is normally quoted at full container load. Small trial orders and mixed-size orders are accepted. Send your size list and we will confirm what can be combined in one shipment.
Q15: How are 45 degree butt weld elbows packed and marked?
Flanges and fittings are packed in plywood cases or on plywood pallets with anti-rust treatment, strapped and stretch-wrapped for sea freight. Each piece carries the heat number, and the material, size, standard and pressure class or schedule are marked on the item or on the case label. Shipping marks are printed to your specification, and a fumigation certificate is provided where wooden packaging is used.
Q16: Can you produce 45 degree butt weld elbows to our drawing or to non-standard specifications?
Yes. Send the drawing, material, quantity and the applicable standard, and we will confirm feasibility and quote. Non-standard angles, non-standard schedules, special materials and special dimensions are produced against your drawing. The details we need to quote are listed on our custom service page. The details we need to quote are listed on our custom service page.
Engineer's Note
Four things decide whether a 45 degree elbow performs on site.
Standard coverage. ASME B16.9 covers the 45° elbow in long radius only. A short radius 45° is not a catalogue item — it is made to drawing, which changes both lead time and price. If a drawing calls for it, expect a fabrication, not a stock fitting.
Take-off. The center-to-end dimension of a 45° elbow is not half of a 90° elbow's. When a 90° is replaced by two 45s and a spool, the take-off comes from the B16.9 dimensions, not from estimation. This is where prefabricated spools end up short or long.
Flow and erosion. A 45 degree turn sheds less energy than a 90 degree turn: lower pressure drop, less erosion at the outer radius. On two-phase or abrasive service, two 45s with a spool outlast a single 90.
Weld count. Two 45s plus a spool means three welds where one 90 would mean two. More welds is more cost and more to inspect. Trade it against the flow benefit deliberately, not by habit.
Enquiry
Send the size, the schedule, the angle and radius, the quantity and the service. A drawing or a line list works just as well. We usually quote within 24 hours.
Frequently Asked Questions
Is a 45 degree elbow long radius or short radius?
ASME B16.9 covers the 45 degree elbow in long radius, and that is what we supply as standard. A short radius 45 degree elbow is not a standard catalogue item under B16.9 or B16.28; where the layout needs one, it is fabricated to your drawing.
How is the center-to-end dimension of a 45 degree elbow determined?
It is taken from the ASME B16.9 tables for the size and schedule, not calculated by rule of thumb. Send us the size and schedule and we will confirm the dimension at quotation stage, so the spool take-off is right the first time.
Can two 45 degree elbows replace a single 90 degree elbow?
Yes, and it is common practice on lines where flow matters. The turn is gentler, so pressure drop and erosion both drop. The take-off changes though: two 45s plus a spool is not the same length as one 90, so the layout has to be recalculated from the standard dimensions.
Does using two 45s instead of one 90 change the pressure drop?
It lowers it. A 45 degree turn sheds less energy than a 90 degree turn, and the space between the two elbows lets the flow re-establish before the next change of direction. The trade-off is one more girth weld to make and inspect.
Are 45 degree elbows available in stainless steel or alloy grades?
Carbon steel to ASTM A234 WPB is our standard supply. Stainless grades such as ASTM A403 WP304 and WP316L, and alloy grades such as ASTM A234 WP11 and WP22, are supplied on request against the same dimensional standard.
What wall thickness should I specify for a 45 degree elbow?
The same schedule as the connecting pipe. There is no separate thickness table for the elbow: the bore and the wall follow the pipe. State the schedule at quotation stage and the fitting is matched to it.
Are the ends bevelled, and can I get a different bevel?
Standard supply is bevelled to ASME B16.25, which fixes the bevel angle, the root face and the land. If your welding procedure calls for something else, send the bevel detail with the enquiry.
Can 45 degree elbows be supplied in welded construction?
Yes, for sizes above the standard seamless range. Welded construction is the normal route for large diameters; the seam weld is examined the same way as any welded fitting, and RT can be specified at quotation stage.
Is a 45 degree elbow suitable for piggable lines?
A standard long radius 45 degree elbow to ASME B16.9 keeps the bore full and is piggable. What stops a pig is not the 45 degree angle, it is a mitred bend, a short radius fitting in a tight size, or a bore step at a weld where the wall thicknesses do not match.
Can you add our own item code or tag to the fittings?
Yes. Standard marking covers the grade, size, schedule, standard and heat number, and we can add your item code, a low-stress stamp or a paint stencil. Tagged and labelled packing for project orders is arranged on request.
What sizes and pressure ratings are available for 45 degree butt weld elbows?
NPS 1/2 inch to 24 inch as standard in seamless construction, with larger sizes in welded construction on request. Wall thickness is specified by pipe schedule. Sizes and ratings outside this range can be reviewed against your drawing. The exact range confirmed for your order is stated in the quotation.
How is the wall thickness determined for 45 degree butt weld elbows?
Butt-weld fittings do not carry a pressure class. Wall thickness is specified by the pipe schedule (SCH 10 / 20 / 40 / 80 / 120 / 160 / XS / XXS), and the schedule must be stated when you request a quotation.
What is the lead time for 45 degree butt weld elbows?
Standard sizes in regular material normally take 7-15 days. Non-standard sizes, special materials and custom orders take longer. The exact lead time for this product is given in the specification table on this page and is confirmed in writing with your quotation. Sea freight to the Gulf is additional and depends on the destination port. All lead times are subject to the production schedule at the time of order.
Is there a minimum order quantity for 45 degree butt weld elbows?
There is no fixed minimum. Standard items can ship from a single pallet, and custom production is normally quoted at full container load. Small trial orders and mixed-size orders are accepted. Send your size list and we will confirm what can be combined in one shipment.
How are 45 degree butt weld elbows packed and marked?
Flanges and fittings are packed in plywood cases or on plywood pallets with anti-rust treatment, strapped and stretch-wrapped for sea freight. Each piece carries the heat number, and the material, size, standard and pressure class or schedule are marked on the item or on the case label. Shipping marks are printed to your specification, and a fumigation certificate is provided where wooden packaging is used.
Can you produce 45 degree butt weld elbows to our drawing or to non-standard specifications?
Yes. Send the drawing, material, quantity and the applicable standard, and we will confirm feasibility and quote. Non-standard angles, non-standard schedules, special materials and special dimensions are produced against your drawing. The details we need to quote are listed on our custom service page.
Related products
- 90° butt weld elbows
- 180° return bends
- carbon steel butt weld tees
- EN 10204 3.1 material certificate