You wouldn't require multiple coupons if this is for performance qualification.
Standard Designation: BPV Section IX
Edition/Addenda: 2015
Para./Fig./Table No: QW-304.1
Subject Description: SC IX; QW-304.1 - Number of Test Coupons
Date Issued: 05/18/2017
Record Number: 16-2602
Interpretation Number : BPV IX-17-17
Question(s) and Reply(ies):
Question (1): Does it meet Code requirements that when doing a performance test on a 1" diameter coupon, the specimens shall be removed according to QW-463.2(d) and the size of the coupon would follow figure QW-462.3(a), note (b) and cut into quarter sections and bent utilizing only one test coupon?
Reply (1): Yes.
Question (2): Does the last statement of QW-304.1 starting with "Alternatively", this part of the section, including sub sections (a), (b) and (c) all describe qualification of the welder utilizing production welds and the reference to 6" length deal entirely with volumetric NDE?
Reply (2): Yes.