Abstract: The present invention relates to a pig for use in a system for lining ducts such as water or sewage pipes or electrical ducts or gas pipes. The pig is insertable at least partly within a fabric liner sleeve located in a duct such as a water or sewage pipe and is capable of heating the liner sleeve in situ in the duct to melt or soften thermoplastic material of the liner sleeve to subsequently form, on cooling of the melted thermoplastic material, a rigid liner in the duct.

Abstract: The present invention relates to a pig for use in a system for lining ducts such as water or sewage pipes or electrical ducts or gas pipes. The pig is insertable at least partly within a fabric liner sleeve located in a duct such as a water or sewage pipe and is capable of heating the liner sleeve in situ in the duct to melt or soften thermoplastic material of the liner sleeve to subsequently form, on cooling of the melted thermoplastic material, a rigid liner in the duct.

Abstract: The present disclosure relates to a pig which is insertable at least partly within a fabric liner sleeve located in a duct and which is capable of heating the liner sleeve in situ in the duct to melt thermoplastic material of the liner sleeve to form, on subsequent cooling of the melted thermoplastic material, a rigid liner in the duct. The pig comprises: a gas inlet (1008) for receiving pressurised gas; a heating chamber (17) in which the pressurised gas is heated; and a gas outlet (1009) via which pressurised gas heated in the heating chamber (17) is deliverable to the fabric liner sleeve. The pig comprises a tree diffuser (15) located in the heating chamber (17) via which pressurised gas can be delivered into the heating chamber (17). The tree diffuser (15) has a plurality of branch pipes (A,B,C) each comprising at least one gas delivery aperture, each branch pipe (A,B,C) extending outwardly from a trunk portion of the tree diffuser (15).