Overview Other Details Reviews Product Description Brass union set 1 1/4" female connection for connecting a Grundfos circulator pump to pipework. Rp = 1 1/4". Other Details 2 years Product Videos Custom Field Product Reviews Write a Review Write a Review × Grundfos Union set 509971 Rating * Select Rating 1 star (worst) 2 stars 3 stars (average) 4 stars 5 stars (best) Name Email * Review Subject * Comments *