Supports in Cold insulated piping

For my current project we have procured shoe supprots for cold insulated piping. The support consists of preformed PUF blocks. The PUF blocks are made of 2 halves. In assembled condition the PUF blocks do not touch each other i.e. they do not cover 180 Deg (since made in 2 half) but a gap of about 10mm is kept. Manufacturer (PSS UK) claims that this gap is required to absorb the expansion and contraction of the piping. Our client does not agree with this arrangement and they insist that the gaps should not exist i.e. the PUF blocks should touch each other at the ends rather than having 6-10mm gap at the ends. Can some one clarify if the gaps are fine.

Your client can protest all they like but the manufactures standards and guidelines are there to be followed... besides if it was manufactured with a 10mm gap on either side how does the client see it being filled? I can only assume it was designed not to be torqued down untill the gap is closed...