A seal assembly for an HVAC system includes a first block having a first aperture and a first sealing surface, a second block having a second aperture and a second sealing, and a conduit having a tube portion with an axially extending aperture and a flange extending radially outwardly from an end of the tube portion. The tube portion is disposed within the first aperture of the first block and the flange is disposed between the first sealing surface of the first block and the second sealing surface of the second block and is configured to deform when compressed therebetween. The seal assembly further includes an insert providing fluid communication between the aperture of the tube portion and the second aperture of the second block. A first end of the insert is received in the aperture of the tube portion of the conduit.