📘 How to Read a Twist Angle

A twist angle indicates the rotational position of a hose fitting in relation to a reference point, typically the fixed end of the hose assembly. In this example, the front fitting represents the starting position (0°), while the back fitting shows the adjusted angle.  

As you move the slider, the back fitting turns counter clockwise, demonstrating how it would be positioned during hose assembly. Use this tool to visualize exact angular alignments — for example, a 90° twist angle means the fitting is turned a quarter rotation to the right from the reference.  

Twist angles are critical for proper hose routing, performance, and clearance in aerospace applications.

🔧 What Is On Our ID Bands

Each hose manufactured at HP Aviation Hoses is fitted with a precision-engraved stainless steel ID tag that provides vital traceability and compliance details. The Tag Diagram outlines what each line on this tag represents, including the  HP job number, Stratoflex part number, customer reference, ATSO approvals, manufacturing and test data, and maximum operating pressure. This ensures every hose meets strict aviation standards and can be quickly identified and verified during service or inspection.

How To Measure Twist Angles

How To Measure A 90° To 90° Flare Hose Assembly

To measure a 90° to 90° flare hose assembly, take the measurement from the centerline of one 90-degree fitting to the centerline of the opposite 90-degree fitting. This is referred to as measuring from Seat to Seat or Flare to Flare. Despite the elbows being angled, the measurement must be taken in a straight, horizontal line between the fittings. All measurements are recorded in eighths of an inch to maintain precision and meet aviation industry standards. This ensures the hose fits correctly in its installed configuration, avoiding unnecessary tension or misalignment.

How To Measure A 45° To 45° Flare Hose Assembly

For a 45° to 45° hose assembly, measure from the center of the flare seat on one 45-degree fitting to the center of the opposite 45-degree fitting. This is called a Seat to Seat or Flare to Flare measurement. The measurement should be taken in a direct straight line between the centers of the fittings, not along the curvature of the hose. All lengths are specified in eighths of an inch, providing the accuracy needed for custom hose routing in aviation and high-performance systems.

How To Measure A 45° To 90° Flare Hose Assembly

When measuring a 45° to 90° hose assembly, measure from the center of the 45-degree fitting to the centerline of the 90-degree fitting. This measurement—known as Seat to Seat or Flare to Flare—must be taken straight across, not along the hose body or angled paths. It’s important to record the final length in eighths of an inch, ensuring the hose meets exact specifications for installation and routing, especially in tight or complex assemblies.

Measuring Hose Assembly's 

How To Measure A Straight To Straight Flare Hose Assembly

To accurately measure a Straight to Straight hose assembly, take the measurement from the center of one fitting to the center of the opposite fitting. This is known as measuring from Seat to Seat or Flare to Flare. Measuring this way captures the true operational length of the hose when installed. By referencing the midpoint of each nut, you ensure correct fitment, minimize stress on components, and reduce the risk of leaks or misalignment.

➡️ All hose lengths should be recorded in eighths of an inch to meet aviation and precision industry standards.

How To Measure A Straight To 45° Flare Hose Assembly

When measuring a hose assembly with a Straight fitting on one end and a 45-degree fitting on the other, measure from the center of the straight fitting to the centerline of the 45-degree fitting. This is commonly referred to as measuring from Seat to Seat or Flare to Flare. Be sure to take the measurement along the central axis of the hose—not at an angle.

➡️ This method ensures the hose length accounts for the correct installation geometry, delivering a precise fit within your system. All hose assemblies are measured in eighths of an inch for maximum accuracy.

How To Measure A Straight To 90° Flare Hose Assembly

To measure a Straight to 90-degree hose assembly accurately, start from the center of the straight fitting and measure to the centerline of the 90-degree fitting. This is referred to as a Seat to Seat or Flare to Flare measurement. Be sure to measure in a straight line, not around the curve of the elbow.➡️ This approach ensures your hose reflects real-world installation length and avoids fitting stress. All measurements should be taken in eighths of an inch, following aviation-grade standards.