... tube Solar Collector 1. EN12975, Solar key mark,SRCC,CE,ISO. 2. 0.68~0.73 premium conversion Vacuum tube solar ... collectors -- Keymark/EN-12975,SRCC,ISO,CE,CCC Feature: Working principle1) When the discrepant temperature of ... ,20mm,22mm, 24mm) optional, will quote per requestMax.working temp-30 ~250CΔT35C(Radiation>=800w/m2.day)Start-up Temperature<=30CResistant ...