To measure spigot size accurately, you need to determine the diameter, which is typically taken at the base of the tail. For spigot sizes over Ø100mm, the measurement is specifically taken on the inside diameter (ID).
Understanding Spigot Measurement
Measuring spigot size is crucial for ensuring a proper fit when connecting pipes or components. The measurement method can vary depending on the spigot's size and the industry standards being followed.
- General Measurement: Typically, spigot size refers to its diameter.
- Location: This diameter is usually measured at the part of the spigot that inserts into another fitting – often called the "tail" or "spigot end" – specifically at its base before any taper.
Measuring Spigots Over Ø100mm
According to the provided reference, for spigot sizes larger than Ø100mm:
- The measurement is taken on the inside diameter (ID).
- This measurement point is at the base of the tail of the spigot.
This is important because the outside diameter (OD) will be larger due to the material thickness. For instance, if the spigot is made from 2mm thick stainless steel, the OD at the base of the tail will be 4mm greater than the stated ID (2mm thickness on each side of the diameter).
Why ID vs. OD Matters
Understanding whether a size refers to the ID or OD is vital for compatibility.
- ID (Inside Diameter): Measures the hole or the hollow space within a pipe or fitting.
- OD (Outside Diameter): Measures across the material from one outer edge to the opposite outer edge.
When a spigot is measured by its ID (especially over Ø100mm as specified), it means the stated size is the diameter of the void within the spigot's tube wall at the base of the tail. The part that actually inserts might be slightly smaller than this ID or designed to fit snugly into a fitting with an internal dimension matching this ID.
Practical Measurement Steps
- Identify the Spigot Tail: Locate the end of the spigot designed to be inserted into another component.
- Locate the Base: Find the point at the very beginning of this tail, usually where it transitions from the main body or before any significant taper begins.
- Measure the Diameter:
- For sizes over Ø100mm: Use a caliper or measuring tape to measure the inside diameter (ID) across the opening at the base of the tail. Ensure the measurement is taken straight across the center.
- Be aware that the outside diameter (OD) will be larger due to the material thickness (e.g., 4mm larger for 2mm stainless steel).
Example Measurement
Let's say you have a stainless steel spigot that is stated to be Ø150mm, and it's confirmed to be over Ø100mm measurement criteria applies.
- The stated size (Ø150mm) refers to the Inside Diameter (ID) at the base of the tail.
- If the material is 2mm thick stainless steel, the Outside Diameter (OD) at that same point would be approximately Ø154mm (Ø150mm ID + 2mm wall thickness + 2mm wall thickness).
This clarifies how spigot sizes, particularly larger ones, are typically defined and measured based on industry practice and the reference provided.