How to choose a fibre optic splice protector

A suitable splice protector must match the fibre construction, splice-tray holder, installation method and project requirements at the same time. There is no single size that is best for every installation. This guide shows how to narrow the V-Protect range down to the right series group.

Choose a splice protector in six steps

1. Identify the fibre type: 250 µm, 900 µm or ribbon

The 250 and 900 µm descriptions refer to different fibre constructions before the splice is prepared. Fibre with a 250 µm primary coating can usually use very compact protectors. Fibre buffered to 900 µm needs more entry space. Multi-fibre ribbons require protectors with a different cross-section, such as the VRA and VRB series.

Do not base the decision on the cable description alone. Check the actual diameter of the components entering the protector, the prepared length and the tray construction. When dimensional clearance is small, confirm the selection on a sample.

2. Choose the installation method: heat-shrink or crimp

Heat-shrink protectors use heat-shrink tubing and a reinforcing element. They form a broad family of series with different diameters, lengths and rigidity. Installation requires a heating cycle consistent with the product and equipment instructions.

The ANT series is an aluminium crimp protector. It does not require a heat-shrink oven, but it does require the ANT-PT tool. It contains butyl compound, and the body measures a nominal 1.2 × 3.3 × 30 mm after crimping. It is designed for single fibres with a 125/200 or 125/250 µm primary coating.

3. Measure the tray holder and available clearance

The heat-shrink series catalogue lists D, d and L dimensions. Compare them with the holder, cover clearance and adjacent fibre paths. The protector must not be wider than the slot or force incorrect fibre routing. In high-density trays, micro and mini series such as V12 and V15 are common starting points.

4. Match rigidity to fibre routing

The outer diameter and reinforcing-element diameter affect the behaviour of the installed protector. The range includes compact, fast-installation, rigid, extra-strong, large and flexible series. If the tray requires gentler routing, review VMF and VFX. Where greater rigidity is the priority, compare the V24–V30 groups.

5. Select a length that fits the splice and tray

The protector must cover the prepared splice area and fit the holder at the same time. V-Protect offers variants from 10 to 68 mm, depending on the series. The shortest available protector is not always suitable, and a longer protector is not automatically better. Measure the slot, account for the stripped length and check the variants listed for the chosen series.

6. Verify required tests, documents and delivery format

If a project or tender specifies a standard, declaration or test method, verify it for the exact selected series and current document revision. Dimensions alone do not confirm compliance. V-Protect performs tests in its LPT Measurement and Test Laboratory and publishes current data sheets and declarations in the Download section. The ANT product page identifies EN 50411-3-3 and TS 0338/96 requirements.

Quick comparison of V-Protect series

The table points to a product group for further verification. Dimensions are catalogue values; check the exact variant and current technical data sheet before ordering.

Requirement	Series to compare	Catalogue range
No-heat installation, single fibre	ANT	After crimping: 1.2 × 3.3 × 30 mm; 125/200 or 125/250 µm fibre
Very limited space, 250 µm fibre	V12, V15	V12: D 1.2; d 0.35; L 15–45 mm. V15: D 1.5; d 0.5; L 15–45 mm
Compact protector with more internal space	V16	D 1.6; d 1.0; L 20–61 mm
Fast installation with d 1.2 mm internal space	V18, V20, V22	D 1.8 / 2.0 / 2.2; d 1.2; L 20–61 mm
Greater rigidity	V24, V25, V26	D 2.4 / 2.5 / 2.6; d 1.2; L 20–61 mm
Extra-strong protector	V28, V30	D 2.8 / 3.0; d 1.2; V28 L 20–61 mm, V30 L 30–61 mm
Large diameter and long variants	V32, V36	D 3.2 / 3.6; d 1.4; L 45–65 mm, plus 68 mm for V36
Flexible routing	VMF, VFX	VMF: D 1.2; d 0.5; L 10–45 mm. VFX: D 2.3; d 1.4; L 20–60 mm
Ribbon fibre	VRA, VRB	Cross-section designed for ribbon; L 25–45 mm. Exact W/H/D depends on the series

Selection examples

High-density tray and 250 µm fibre

Start with V12 and V15. Compare holder diameter, available length and required rigidity. If more space is available, V16 can provide greater internal clearance.

900 µm buffered fibre

Selection can start with a series having a catalogue inner dimension d of 1.2 mm, such as V18. Confirm the actual construction diameter, tray slot and required rigidity; these factors may point to a wider series.

No heat-shrink oven available

Review the ANT crimp series. Confirm that the fibre is within the stated product range and that the ANT-PT tool is available.

Ribbon-fibre splice

Compare VRA and VRB according to ribbon cross-section, tray-slot dimensions and holder length. Do not replace a ribbon protector with an arbitrarily selected round protector.

What should an enquiry or OEM request include?

• fibre type and actual diameter before splice preparation;
• number of fibres and whether the construction is single, buffered or ribbon;
• tray-holder dimensions: length, width or diameter, plus available clearance;
• preferred installation method: heat-shrink or crimp;
• required length, rigidity and any other construction constraints;
• standards, tests, declarations or documents required by the project;
• planned quantity and expected packaging format.

For non-standard or OEM enquiries, V-Protect can assess an existing series or the feasibility of another solution. Accurate input data helps exclude unsuitable variants quickly.

Frequently asked questions

Which splice protector is best for 250 µm fibre?

There is no single best variant. For very small trays, compare V12 and V15; where more space is available, consider the following series as well. Holder dimensions, length, installation method and required rigidity determine the final choice.

Which series is a starting point for 900 µm buffered fibre?

V18, with a catalogue inner dimension d of 1.2 mm, can be a starting point. Confirm the actual diameter of the complete construction and the available tray space. A different d 1.2 mm series may be more suitable depending on the required rigidity.

When should a crimp protector be selected instead of heat-shrink?

The ANT series is useful when installation must be performed without a heat-shrink oven. It still requires a compatible fibre and the dedicated ANT-PT tool. Heat-shrink series provide a wider choice of diameters, lengths and rigidity.

How should splice-protector length be selected?

Measure the holder and account for the prepared splice area. The protector should cover it, fit the slot and avoid forcing tight fibre routing. Check the list of lengths available for the selected series.

Can an oversized protector cause problems?

Yes. It may not fit the holder, may interfere with the cover or adjacent protectors, and may make correct fibre routing difficult. A larger size should not be chosen without checking tray geometry.

Which protectors are designed for ribbon fibre?

V-Protect offers VRA and VRB series with cross-sections intended for multi-fibre ribbons. The choice between them depends on ribbon cross-section, holder dimensions and required length.

Where can standards and current documentation be checked?

Current technical data sheets and declarations are available on the Download page. Testing capabilities are described on the LPT Laboratory page. Requirements should always be confirmed for the exact series and current document revision.

Can V-Protect supply a non-standard or OEM variant?

Such requirements can be submitted to V-Protect for assessment. Include dimensions, construction, quantity, required documents and packaging format. The team will check whether an existing series can be used or another solution is needed.