A method of forming a pipe joint, the method comprising the steps of: providing a fluid piping system including a series of sections of ductile iron pipe (17,19), each of the pipes having a belled end at one extent with a mouth region adjacent an end opening thereof, the mouth region having an annular groove therein, the end opening being sized to receive a mating male pipe having an interior surface and an exterior surface; installing a sealing gasket within the annular groove provided in the end opening of the belled pipe end, the sealing gasket having an annular gasket body made of a resilient elastomeric material having a defined durometer, the annular gasket body having a leading nose region, an inner circumferential region and an outer circumferential region, the annular gasket body being installed within the annular groove provided in the mouth region of the ductile iron pipe so that the outer circumferential region forms a seal with the pipe belled mouth region and the inner circumferential region forms a sealing surface for the exterior surface of the mating male ductile iron pipe; wherein a plurality of higher durometer wedge shaped retainer inserts (37,39) formed from a plastic having a relatively harder durometer than the elastomeric material of the remaining gasket body are removably installed within and extend outwardly from the annular gasket body along the leading nose region thereof at a predetermined spacing which extends around the circumference of the annular gasket body, the spacing being sufficient to allow the gasket body to be flexed to facilitate the installation of the gasket body within the annular groove provided within the mouth opening of the belled pipe end; and wherein each of the wedge shaped retainer inserts (37,39) has a generally wedge shaped nose portion with opposing sloping sides, the opposing sides being formed as smooth surfaces, the wedge shaped nose portion extending outwardly from the leading nose region of the gasket body to an apex when viewed in cross section, and a trailing leg region which constitutes a flexible retainer portion for the insert (37,39), the trailing leg region having at least two peg shaped retention posts which are installed within suitable retainer openings (47,49) in the nose region of the annular gasket body by pressing the peg shaped retention posts into the openings (47,49), whereby alternate retainer inserts (37,39) can be installed within the same annular gasket body. providing a fluid piping system including a series of sections of ductile iron pipe (17,19), each of the pipes having a belled end at one extent with a mouth region adjacent an end opening thereof, the mouth region having an annular groove therein, the end opening being sized to receive a mating male pipe having an interior surface and an exterior surface; installing a sealing gasket within the annular groove provided in the end opening of the belled pipe end, the sealing gasket having an annular gasket body made of a resilient elastomeric material having a defined durometer, the annular gasket body having a leading nose region, an inner circumferential region and an outer circumferential region, the annular gasket body being installed within the annular groove provided in the mouth region of the ductile iron pipe so that the outer circumferential region forms a seal with the pipe belled mouth region and the inner circumferential region forms a sealing surface for the exterior surface of the mating male ductile iron pipe; wherein a plurality of higher durometer wedge shaped retainer inserts (37,39) formed from a plastic having a relatively harder durometer than the elastomeric material of the remaining gasket body are removably installed within and extend outwardly from the annular gasket body along the leading nose region thereof at a predetermined spacing which extends around the circumference of the annular gasket body, the spacing being sufficient to allow the gasket body to be flexed to facilitate the installation of the gasket body within the annular groove provided within the mouth opening of the belled pipe end; and wherein each of the wedge shaped retainer inserts (37,39) has a generally wedge shaped nose portion with opposing sloping sides, the opposing sides being formed as smooth surfaces, the wedge shaped nose portion extending outwardly from the leading nose region of the gasket body to an apex when viewed in cross section, and a trailing leg region which constitutes a flexible retainer portion for the insert (37,39), the trailing leg region having at least two peg shaped retention posts which are installed within suitable retainer openings (47,49) in the nose region of the annular gasket body by pressing the peg shaped retention posts into the openings (47,49), whereby alternate retainer inserts (37,39) can be installed within the same annular gasket body.